Flox as a Guided Path for Nix

Flox aims to simplify software delivery by leveraging Nix. This presentation explores lessons from years of building developer tools and cloud-native systems. Discover how Nix is the key building block, addressing complexities in modern application delivery. The talk emphasizes a guided path for adoption, enabling teams to modernize without needing a Nix expert in every department. Dive into the underlying mindset of Flox's approach to evolving software practices for a simpler experience.

Delivered at Planet Nix 2025, March 07, 2025.

Transcript

1. Flox as a Guided Path for Nix Michael Stahnke VP Engineering at Flox (flox.dev) @stahnma
2. 2 Not a sales pitch @stahnma
3. 3 Thoughts and approach @stahnma
4. Edu Career 4 9 Years 8 Years 4 Years About a Year
6. 6 Packaging and Software • Founded EPEL repository • Maintained more than 200 packages for Fedora • Ported Ruby to AIX • Packaged for AIX, Debian, Red Hat, Solaris, Mac, Windows, Arista Switches, Cisco Nexus Gear, etc @stahnma
7. 7 For 15 years, I’ve been doing developer and infrastructure tooling @stahnma
8. 8 @stahnma
10. 10 Result: Didn’t touch it again for years. @stahnma
11. 11 Packaging All the Things @stahnma
12. 12 Wrote our own tooling @stahnma
13. 13 Built our own CI system from the ground up @stahnma
14. 14 Nix solved portions of that @stahnma
15. 15 I <3 Packaging I <3 Developer productivity Let’s do this. @stahnma
16. 16 A New Nix User
17. 17 Why is this so complicated? @stahnma
18. 18 Expression Profile Derivation Purity Shell Flakes Closure (not Clojure) Storepath Purity @stahnma
19. 19 There are debates about what “install” means… @stahnma
20. 20 Other problems Can’t find headers Can’t find libraries Shell vs develop Experimental Features Is this a package manager, a package repository, an OS, or a tool? @stahnma
21. 21 Commands with spaces all need extra arguments saying it’s ok to use commands with spaces @stahnma
22. 22 You start with a build…then you write code? @stahnma
23. 23 Nix starts in the deep end @stahnma
24. 24 So, let’s take a step back @stahnma
25. 25 What’s nix awesome at? @stahnma
26. 26 Nix Benefits • Reproducibility • Cross Platform • Trying out software • Caching builds and tests • Huge Package Repository @stahnma
29. 29 Tangent
30. Customer Viewpoints 30
31. 31 @stahnma
32. 32 @stahnma
33. 33 @stahnma
34. Everyone knows that debugging is twice as hard as writing a program in the first place. So if you're as clever as you can be when you write it, how will you ever debug it? — Brian Kernighan 34
35. 35 Back to our regular program
36. 36 Desire for simplicity. @stahnma
37. 37 Desire for nix benefits. @stahnma
38. 38 Desire for Cross Platform Work @stahnma
39. Workflows 39 • Have a way to contribute to a project (locally usually) • Set environment variables in some way • Configure the environment • Run Tests • Have development look like something that will run in prod • Use my editor • Use my preferences @stahnma
41. 41 Why? @stahnma
42. 42 Can we build upon the last 20 years of Cloud? @stahnma
43. 43 Can we build upon the last 20 years of Nix? @stahnma
44. 44 Can we do this without abandoning existing knowledge sets? @stahnma
46. Thrown away concepts using cloud native architecture 46 Multiuser systems Multi-application systems Debugging using a shell Process and User accounting @stahnma
47. Added complexity when using Cloud Native 47 Debugging tools Observability tooling IAM Paying for services to monitor services to run services to monitor services YAML…fun? Sure. Fun. @stahnma
48. Peel back the complexity Onion 48 There is a lot to like about Cloud Native Architectures. @stahnma
49. Peel back the complexity Onion 49 There is a lot to like about traditional Unix/Linux concepts. @stahnma
50. Peel back the complexity Onion 50 Why are these mutually exclusive? @stahnma
51. Peel back the complexity Onion 51 Build on the power of nix. @stahnma
52. Peel back the complexity Onion 52 Build on the simplicity of an environment you can work with in your shell. @stahnma
53. What workflows matter to a user? 53
54. 54 Search, install packages @stahnma
55. 55 Specific versions of packages @stahnma
56. 56 No variance @stahnma
57. 57 Develop, then build, then operate @stahnma
58. 58 Partial SDLC adoption @stahnma
59. Peel back the complexity Onion 59 Starting with the build is unfamiliar @stahnma
60. Peel back the complexity Onion 60 Share your environments with colleagues, production, friends, strangers @stahnma
61. 61 Hypothetical Learning Curve @stahnma
62. Peel back the complexity Onion 62 If you know nix, great. Perhaps this can help with others on your team or department. @stahnma
63. Peel back the complexity Onion 63 If you’re new to nix, I hope this an easier approach. @stahnma
64. Peel back the complexity Onion 64 Modern SDLC wants what nix brings. @stahnma
65. 65 Nix Benefits • Reproducibility • Cross Platform • Trying out software • Caching builds and tests • Huge Package Repository @stahnma
66. 66 Approach • Centered around “Environments” • They can be used at any time in the SDLC • They are portable • They are sharable • They are built upon nix and share some of the best nix benefits. • They are not 1:1 Nix • Packaged software versions over time • Auditable @stahnma
67. 67 Approach • Meet technologists where they are • Compatibility with existing SDLC approaches, tools, processes • The developer experience is paramount @stahnma
68. flox.dev