Coldstart - why should you care and how? (DroidCon 2016, NY)

How can you quantify, measuring and analyzing startup time on a continuous basis? In this talk, we start up with a concrete definition of coldstart and describe techniques to measure it both as a part of continuous integration and from the field.

We then look at how to visualize and analyze this data using standard Android performance tools and visualization tools we built. And to end it off, we talk about some strategies we've used to optimize the startup process.

Transcript

1. Coldstart Why should you care and how? @vikramb0
2. Users want fast AppDynamics
3. Users want fast • 20% ➔ apps should load instantaneously AppDynamics
4. Users want fast • 20% ➔ apps should load instantaneously • 36% ➔ slow performance = company sucks AppDynamics
5. Users want fast • 20% ➔ apps should load instantaneously • 36% ➔ slow performance = company sucks • 86% ➔ uninstall at least 1 sluggish app after one use AppDynamics
6. What’s fast enough?
7. What’s fast enough? • > 3 seconds ➔ 53% drop-off (Google)
8. What’s fast enough? • > 3 seconds ➔ 53% drop-off (Google) • < 2 seconds ➔ top 40% of the apps (NimbleDroid)
9. Coldstart Tap on icon ➔ Application starts? Activity starts? Data loaded?
10. Coldstart Tap on icon ➔ Application starts? Activity starts? Data loaded?
11. Coldstart Tap on icon ➔ Application starts? Activity starts? Data loaded?
12. Coldstart Tap on icon ➔ Application starts? Activity starts? Data loaded?
13. MIP first
14. MIP first • First most important pixel
15. MIP first • First most important pixel • Your MIP definition is built into your UI design
16. MIP first • Indices representing market status • The user’s watchlist
17. MIP first • Indices representing market status • The user’s watchlist
18. MIP first • Indices representing market status • The user’s watchlist
19. MIP first • Watchlist > Indices • Up-to-date quotes
20. –Your user “tap on icon ➔ I have something useful”
21. Our goal Median coldstart of 2000ms in production on your most popular device on WiFi
22. Our goal Median coldstart of 2000ms in production on your most popular device on WiFi
23. Our goal Median coldstart of 2000ms in production on your most popular device on WiFi Median
24. Our goal Median coldstart of 2000ms in production on your most popular device on WiFi
25. Our goal Median coldstart of 2000ms in production on your most popular device on WiFi
26. Our goal Median coldstart of 2000ms in production on your most popular device on WiFi
27. Our goal
28. Our goal • Maximize benefit/cost
29. Our goal • Maximize benefit/cost • Stay fast consistently
30. Our goal • Maximize benefit/cost • Stay fast consistently • Automate
31. The plan • Define • Measure • A DIY performance-degradation alerting system • Fail early • Performance catalog
32. The plan • Define • Measure • A DIY performance-degradation alerting system • Fail early • Performance catalog
33. The plan • Define • Measure • A DIY performance-degradation alerting system • Fail early • Performance catalog
34. What’s coldstart? • User taps on the application to • no content • cached data* • fresh data
35. What’s coldstart?
36. What’s coldstart? • Apps can startup in multiple ways • cold starts, warm starts, notifications, deep links etc
37. What’s coldstart? • Apps can startup in multiple ways • cold starts, warm starts, notifications, deep links etc • Keep special cases in mind • first launch, on-boarding flows, network failures
38. Application Activity TrendingTickers Quotes
39. Time First line of code Cached data Fresh content Icon tap Layout loaded
40. Time First line of code Cached data Fresh content Icon tap Layout loaded
41. Time First line of code Cached data Fresh content Icon tap Layout loaded
42. 
 appInteractive = layoutLoaded - firstLineOfCode; Time First line of code Cached data Fresh content Icon tap Layout loaded
43. Time First line of code Cached data Fresh content Icon tap Layout loaded
44. 
 cachedDataLoaded = cachedDataLoaded - firstLineOfCode; Time First line of code Cached data Fresh content Icon tap Layout loaded
45. Time First line of code Cached data Fresh content Icon tap Layout loaded
46. coldstart = freshContent - firstLineOfCode; Time First line of code Cached data Fresh content Icon tap Layout loaded
47. Where are we spending time?
48. Where are we spending time? Debug.startMethodTracing();
 …
 Debug.stopMethodTracing();
49. Where are we spending time? Debug.startMethodTracing();
 …
 Debug.stopMethodTracing();
50. Phases • Section of code • Network calls • Initializing SDKs • Data processing
51. Phases
52. Phases reporter.startPhase(“fetchTrendingTickers”);
 …
 reporter.endPhase(“fetchTrendingTickers”);
53. Phases reporter.startPhase(“fetchTrendingTickers”);
 …
 reporter.endPhase(“fetchTrendingTickers”);
54. Visualizing phases
55. Visualizing phases
56. Capturing coldstart Application Activity TrendingTickers Quotes ColdstartRegister
57. Capturing coldstart Application Activity TrendingTickers Quotes ColdstartRegister
58. Capturing coldstart Application Activity TrendingTickers Quotes ColdstartRegister
59. Capturing coldstart Application Activity TrendingTickers Quotes ColdstartRegister
60. Capturing coldstart Application Activity TrendingTickers Quotes ColdstartRegister
61. Capturing coldstart Application Activity TrendingTickers Quotes ColdstartRegister
62. Capturing coldstart Application Activity TrendingTickers Quotes ColdstartRegister ProdReporter
63. public class Stopwatch { }
64. public class Stopwatch { public void markEvent(String event) { //Record event time SystemClock.elapsedRealtime(); } }
65. public class Stopwatch { public void markEvent(String event) { //Record event time SystemClock.elapsedRealtime(); } } SystemClock.currentTimeMillis(); SystemClock.uptimeMillis(); SystemClock.elapsedRealtimeNanos();
66. public class Stopwatch { public void markEvent(String event) { //Record event time SystemClock.elapsedRealtime(); } } SystemClock.currentTimeMillis(); SystemClock.uptimeMillis(); SystemClock.elapsedRealtimeNanos();
67. public class Stopwatch { public void markEvent(String event) { //Record event time SystemClock.elapsedRealtime(); } } SystemClock.currentTimeMillis(); SystemClock.uptimeMillis(); SystemClock.elapsedRealtimeNanos();
68. public class Stopwatch { public void markEvent(String event) { //Record event time SystemClock.elapsedRealtime(); } } SystemClock.currentTimeMillis(); SystemClock.uptimeMillis(); SystemClock.elapsedRealtimeNanos();
69. public enum Event {
 APP_ON_CREATE_BEGIN,
 APP_ON_CREATE_END,
 ACT_ON_CREATE_BEGIN,
 APP_INTERACTIVE, TICKERS_LOADED, QUOTES_LOADED }
70. public class ColdstartRegister { public void updateState(Event event) {
 stopwatch.markEvent(event.name()); if(stopwatch.isMarked(Event.TICKERS_LOADED) && stopwatch.isMarked(Event.QUOTES_LOADED)){
 //Report cachedData
 }
 } }
71. public class ColdstartRegister { public void updateState(Event event) {
 stopwatch.markEvent(event.name()); if(stopwatch.isMarked(Event.TICKERS_LOADED) && stopwatch.isMarked(Event.QUOTES_LOADED)){
 //Report cachedData
 }
 } }
72. public class ColdstartRegister { public void updateState(Event event) {
 stopwatch.markEvent(event.name()); if(stopwatch.isMarked(Event.TICKERS_LOADED) && stopwatch.isMarked(Event.QUOTES_LOADED)){
 //Report cachedData
 }
 } }
73. public class MyApp extends Application {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate();
 }
 } Application Activity TrendingTickers Quotes
74. Application Activity TrendingTickers Quotes public class MyApp extends Application {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); reporter.updateState(Event.APP_ON_CREATE_BEGIN);
 }
 }
75. public class MyApp extends Application {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); reporter.updateState(Event.APP_ON_CREATE_BEGIN); //Do your work
 }
 } Application Activity TrendingTickers Quotes
76. public class MyApp extends Application {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); reporter.updateState(Event.APP_ON_CREATE_BEGIN); //Do your work reporter.updateState(Event.APP_ON_CREATE_END);
 }
 } Application Activity TrendingTickers Quotes
77. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate();
 }
 } Application Activity TrendingTickers Quotes
78. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); reporter.updateState(Event.ACT_ON_CREATE_BEGIN);
 }
 } Application Activity TrendingTickers Quotes
79. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); reporter.updateState(Event.ACT_ON_CREATE_BEGIN); 
 fetchTrendingTickers(…, new Listener() {
 @Override
 public void onResponse(final Response response) { showTrendingTickers(response.getTickers()); } });
 }
 } Application Activity TrendingTickers Quotes
80. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); reporter.updateState(Event.ACT_ON_CREATE_BEGIN); 
 fetchTrendingTickers(…, new Listener() {
 @Override
 public void onResponse(final Response response) { showTrendingTickers(response.getTickers()); reporter.updateState(Event.TICKERS_LOADED); } });
 }
 } Application Activity TrendingTickers Quotes
81. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() { …
 } @Override
 public void onResume() {
 super.onResume(); }
 } Application Activity TrendingTickers Quotes
82. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() { …
 } @Override
 public void onResume() {
 super.onResume(); reporter.updateState(Event.APP_INTERACTIVE);
 }
 } Application Activity TrendingTickers Quotes
83. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 public void loadQuotes(List<String> symbols) {
 fetchQuotes(…, new Listener() {
 @Override
 public void onResponse(final Response response) { updateQuotes(response.getQuotes()); reporter.updateState(Event.QUOTES_LOADED); } });
 }
 } Application Activity TrendingTickers Quotes
84. Capturing phase information public class Stopwatch { public void startPhase(String phase) { } public void endPhase(String phase) { } public void markEvent(String phase, String event) { } }
85. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); … 
 fetchTrendingTickers(…, new Listener() {
 @Override
 public void onResponse(final Response response) { showTrendingTickers(response.getTickers()); … } });
 }
 } Application Activity TrendingTickers Quotes
86. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); … reporter.startPhase(“fetchTrendingTickers”);
 fetchTrendingTickers(…, new Listener() {
 @Override
 public void onResponse(final Response response) { showTrendingTickers(response.getTickers()); … reporter.endPhase(“fetchTrendingTickers”); } });
 }
 } Application Activity TrendingTickers Quotes
87. public class MyActivity extends Activity {
 private ColdstartRegister register;
 
 @Override
 public void onCreate() {
 super.onCreate(); … reporter.startPhase(“fetchTrendingTickers”);
 fetchTrendingTickers(…, new Listener() {
 @Override
 public void onResponse(final Response response) { showTrendingTickers(response.getTickers()); … reporter.endPhase(“fetchTrendingTickers”); } });
 }
 } Application Activity TrendingTickers Quotes
88. Extracting data from the Stopwatch public class Stopwatch { … }
89. Extracting data from the Stopwatch public class Stopwatch { … } public interface Reporter { public void reportAll(…) { } }
90. Extracting data from the Stopwatch public class Stopwatch { … public void reportAll(Reporter dumper) { //Dump all events } } public interface Reporter { … }
91. The plan • Define • Measure • A DIY performance-degradation alerting system • Fail early • Performance catalog
92. Telemetry - automatic measurement and wireless transmission of data from remote sources
93. … Telemetry
94. … POST /performance Telemetry
95. … POST /performance Telemetry {
 "coldstart": 600, "model": “SM-G900P", "version": “0.1",
 "phases": [
 {
 "name": "phase1",
 "start": 3,
 "dur": 45
 }
 ...
 {
 "name": "phase2",
 "start": 78,
 "dur": 331
 }
 ]
 }
96. … Telemetry POST /performance {
 "coldstart": 720, "model": “LG-H811", "version": “0.1",
 "phases": [
 {
 "name": "phase1",
 "start": 8,
 "dur": 33
 }
 ...
 {
 "name": "phase2",
 "start": 64,
 "dur": 298
 }
 ]
 }
97. … {
 "coldstart": 600, "model": “LG-E977", "version": “0.1",
 "phases": [
 {
 "name": "phase1",
 "start": 11,
 "dur": 84
 }
 ...
 {
 "name": "phase2",
 "start": 66,
 "dur": 293
 }
 ]
 } Telemetry POST /performance
98. Telemetry
99. Telemetry GET /aggregate_coldstart?v=0.1
100. {
 "median_coldstart": 600, "version": “0.1”
 } Telemetry GET /aggregate_coldstart?v=0.1
101. Telemetry
102. Telemetry GET /aggregate_phases?v=0.1
103. {
 "agg_phases": [
 {
 "name": "phase1",
 "agg_start": 3,
 "agg_dur": 45
 }
 ...
 {
 "name": "phase2",
 "agg_start": 78,
 "agg_dur": 331
 }
 ], "version": “0.1”
 } Telemetry GET /aggregate_phases?v=0.1
104. Build your own phase visualizer https://developers.google.com/chart/interactive/docs/gallery/timeline
105. Build your own phase visualizer <html> <body> <div id="timeline" style="height: 180px;”/> </body> </html> https://developers.google.com/chart/interactive/docs/gallery/timeline
106. Build your own phase visualizer <html> <body> <div id="timeline" style="height: 180px;”/> </body> </html> var chart = new google.visualization.Timeline(container); https://developers.google.com/chart/interactive/docs/gallery/timeline
107. Build your own phase visualizer <html> <body> <div id="timeline" style="height: 180px;”/> </body> </html> var chart = new google.visualization.Timeline(container); var dataTable = new google.visualization.DataTable(); https://developers.google.com/chart/interactive/docs/gallery/timeline
108. Build your own phase visualizer <html> <body> <div id="timeline" style="height: 180px;”/> </body> </html> var chart = new google.visualization.Timeline(container); var dataTable = new google.visualization.DataTable(); https://developers.google.com/chart/interactive/docs/gallery/timeline
109. Build your own phase visualizer <html> <body> <div id="timeline" style="height: 180px;”/> </body> </html> var chart = new google.visualization.Timeline(container); var dataTable = new google.visualization.DataTable(); dataTable.addRows([
 [ 'Phase1', start, end],
 [ 'Phase2', start, end]]); https://developers.google.com/chart/interactive/docs/gallery/timeline
110. Build your own phase visualizer <html> <body> <div id="timeline" style="height: 180px;”/> </body> </html> var chart = new google.visualization.Timeline(container); var dataTable = new google.visualization.DataTable(); dataTable.addRows([
 [ 'Phase1', start, end],
 [ 'Phase2', start, end]]); chart.draw(dataTable); https://developers.google.com/chart/interactive/docs/gallery/timeline
111. Build your own phase visualizer <html> <body> <div id="timeline" style="height: 180px;”/> </body> </html> var chart = new google.visualization.Timeline(container); var dataTable = new google.visualization.DataTable(); dataTable.addRows([
 [ 'Phase1', start, end],
 [ 'Phase2', start, end]]); chart.draw(dataTable); https://developers.google.com/chart/interactive/docs/gallery/timeline
112. The plan • Define • Measure • A DIY performance-degradation alerting system • Fail early • Performance catalog
113. Alerting on issues Telemetry
114. Alerting on issues Telemetry
115. Alerting on issues Telemetry
116. Alerting on issues Telemetry GET /aggregate_coldstart
117. Alerting on issues Telemetry GET /aggregate_coldstart > 2000ms?
118. Alerting on issues Telemetry No GET /aggregate_coldstart > 2000ms?
119. Alerting on issues Telemetry Yes No GET /aggregate_coldstart > 2000ms?
120. Alerting on issues Telemetry Yes No GET /aggregate_coldstart > 2000ms?
121. Alerting on issues Telemetry Yes No GET /aggregate_coldstart > 2000ms? Slack
122. Alerting on issues Telemetry Yes No GET /aggregate_coldstart > 2000ms? Slack Email
123. Alerting on issues Telemetry Yes No GET /aggregate_coldstart > 2000ms? Slack Email Text
124. Alerting on issues Telemetry Yes No GET /aggregate_coldstart > 2000ms? Slack Email Text Pigeon
125. Responding to alerts
126. Responding to alerts Telemetry
127. Responding to alerts Telemetry GET /aggregate_coldstart
128. Responding to alerts Telemetry Remote fix? GET /aggregate_coldstart
129. Responding to alerts Telemetry Remote fix? Yes GET /aggregate_coldstart
130. Responding to alerts Telemetry Remote fix? Fix it! Yes GET /aggregate_coldstart
131. Responding to alerts Telemetry Remote fix? Fix it! Yes No GET /aggregate_coldstart
132. Responding to alerts Telemetry Remote fix? Fix it! Yes Cancel that vacation No GET /aggregate_coldstart
133. The plan • Define • Measure • A DIY performance-degradation alerting system • Fail early • Performance catalog
134. Fail early
135. Fail early • Catch regressions as you write code on your CI
136. Fail early • Catch regressions as you write code on your CI • Regression = considerable uptick in coldstart
137. Fail early • Catch regressions as you write code on your CI • Regression = considerable uptick in coldstart • Remove variances - server latency
138. Fail early • Catch regressions as you write code on your CI • Regression = considerable uptick in coldstart • Remove variances - server latency ./gradlew checkForColdstartRegression
139. Fail early ./gradlew checkForColdstartRegression
140. Fail early ./gradlew checkForColdstartRegression
141. Fail early ./gradlew checkForColdstartRegression App code App
142. Fail early ./gradlew checkForColdstartRegression App code App HTTP server
143. Fail early ./gradlew checkForColdstartRegression App code App HTTP server
144. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho
145. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho
146. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart
147. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history
148. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history Get coldstart:commit
149. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history Get coldstart:commit
150. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Get coldstart:commit
151. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? yes Get coldstart:commit
152. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job yes Get coldstart:commit
153. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job yes no Get coldstart:commit
154. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job Pass job yes no Get coldstart:commit
155. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history Write commit:coldstart coldstart - previousColdstart > threshold? Fail job Pass job yes no Get coldstart:commit
156. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job Pass job yes no
157. Fail early ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job Pass job yes no Write commit:coldstart Get coldstart:commit
158. A few moving parts here ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job Pass job yes no
159. A few moving parts here ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job Pass job yes no Write commit:coldstart Get coldstart:commit
160. A few moving parts here ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job Pass job yes no
161. A few moving parts here ./gradlew checkForColdstartRegression App code App HTTP server Stetho coldstart Coldstart history coldstart - previousColdstart > threshold? Fail job Pass job yes no Write commit:coldstart Get coldstart:commit
162. Local HTTP server android { buildTypes {
 production {
 buildConfigField “String", ‘“URL_HOST”’,“myhost.com” } coldstartTest {
 buildConfigField “String", ‘“URL_HOST”’,“127.0.0.1” } } } dependencies { coldstartTestCompile ‘com.nanohttpd:nanohttpd-webserver:2.+’ }
163. Local HTTP server android { buildTypes {
 production {
 buildConfigField “String", ‘“URL_HOST”’,“myhost.com” } coldstartTest {
 buildConfigField “String", ‘“URL_HOST”’,“127.0.0.1” } } } dependencies { coldstartTestCompile ‘com.nanohttpd:nanohttpd-webserver:2.+’ }
164. Local HTTP server android { buildTypes {
 production {
 buildConfigField “String", ‘“URL_HOST”’,“myhost.com” } coldstartTest {
 buildConfigField “String", ‘“URL_HOST”’,“127.0.0.1” } } } dependencies { coldstartTestCompile ‘com.nanohttpd:nanohttpd-webserver:2.+’ }
165. Local HTTP server android { buildTypes {
 production {
 buildConfigField “String", ‘“URL_HOST”’,“myhost.com” } coldstartTest {
 buildConfigField “String", ‘“URL_HOST”’,“127.0.0.1” } } } dependencies { coldstartTestCompile ‘com.nanohttpd:nanohttpd-webserver:2.+’ }
166. Local HTTP server public class ColdStartApp extends MyApp {
 
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 }
 }
167. Local HTTP server public class ColdStartApp extends MyApp {
 
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState); new MyHTTPD().start(); }
 
 private class MyHTTPD extends NanoHTTPD {
 public MyHTTPD() throws IOException {
 super(PORT, null);
 }
 
 @Override
 public Response serve(String uri, …) { serveFileBasedOnUri(uri); }
 }
 }
168. Local HTTP server public class ColdStartApp extends MyApp {
 
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState); new MyHTTPD().start(); }
 
 private class MyHTTPD extends NanoHTTPD {
 public MyHTTPD() throws IOException {
 super(PORT, null);
 }
 
 @Override
 public Response serve(String uri, …) { serveFileBasedOnUri(uri); }
 }
 }
169. Local HTTP server public class ColdStartApp extends MyApp {
 
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState); new MyHTTPD().start(); }
 
 private class MyHTTPD extends NanoHTTPD {
 public MyHTTPD() throws IOException {
 super(PORT, null);
 }
 
 @Override
 public Response serve(String uri, …) { serveFileBasedOnUri(uri); }
 }
 }
170. The plan • Define • Measure • A DIY performance-degradation alerting system • Fail early • Performance catalog
171. Optimize your UI for startup experience
172. Your APIs • Make your APIs fast • Get a first-page API built • Enable data compression on the server-side • Take a look at your caching policies
173. Your Data • Preload data • Use the JobScheduler
174. Some of the more obvious ones • Avoid reflection at all costs • Batch network calls • Know what your SDKs do
175. Some more of the more obvious ones • Avoid resource loading • Ensure that your UI thread and workers are working in sync • Avoid image manipulation and processing
176. Some micro-optimizations • Flatten your UI • Be careful with handler.postAtFrontOfQueue(new Runnable()) • Try and stay under the 65K method limit
177. This is your most important feature