Team Feature Flags
SDK Engineer
Department
Product Engineering
Location
Remote (EMEA, US, US | EU)
Timezone(s)
GMT+ 2:00 to GMT -8:00
About PostHog
We’re equipping every developer to build successful products by giving them a suite of products to analyze, test, observe, and deploy new features. We currently offer product and web analytics, session replay, feature flags, experiments, a CDP, SQL access, a data warehouse, and LLM observability… and there’s plenty more to come.
PostHog was created as an open-source project during Y Combinator's W20 cohort. We had the most successful B2B software launch on HackerNews since 2012 with a product that was just 4 weeks old. Since then, more than 100,000 companies have installed the platform. We've had huge success with our paid upgrades, raised bags of money from some of the world's top investors, and have extremely strong product-led growth – 97% driven by word of mouth.
We're growing quickly, but sustainably. We're also default alive, averaging 10% monthly revenue growth and with more than $20m ARR. We're staying focused on building an awesome product for end users, hiring a handful of exceptional team members, and seeing fantastic growth as a result.
What we value
We are open source - building a huge community around a free-for-life product is key to PostHog's strategy.
We aim to become the most transparent company, ever. In order to enable teams to make great decisions, we share as much information as we can. In our public handbook everyone can read about our roadmap, how we pay (or even let go of) people, what our strategy is, and who we have raised money from. We also have regular team-wide feedback sessions, where we share honest feedback with each other.
Working autonomously and maximizing impact - we don’t tell anyone what to do. Everyone chooses what to work on next based on what is going to have the biggest impact on our customers.
Solve big problems - we haven't built our defining feature yet. We are all about acting fast, innovating, and iterating.
Who we’re looking for
We're looking for a pragmatic polyglot engineer passionate about crafting high-quality developer experiences across a range of languages and platforms. You're someone who thrives on improving SDKs that developers enjoy using — ones that are fast, reliable, and feel native no matter the tech stack.
In this role, you'll focus on our feature flag SDKs, used in server-side apps and infrastructure to power flag evaluation. Some of these SDKs make remote requests to our evaluation engine, while others run locally, meaning correctness and performance are equally critical. Many other PostHog products depend on the SDKs, so you'll be working on critical infrastructure that touches many parts of the company.
You should be deeply familiar with at least one of our primary languages/platforms (Python, Go, Rust, C#, or TypeScript), and confident picking up enough of the others to make meaningful contributions across the SDK ecosystem. You’ll work closely with backend, infra, and product teams to ensure our SDKs remain robust and delightful, while also helping us find ways to support more languages more efficiently.
What makes this role unique
SDKs are the gateway to everything PostHog – You’ll be shaping the developer experience for every customer using our feature flags product, making your work highly visible and impactful.
You’ll work across languages and runtimes – From statically typed servers to dynamic scripting environments, you’ll build idiomatic SDKs that feel like they belong in each language.- You’ll influence local vs. remote flag evaluation strategies – Help us make trade-offs between speed, correctness, and simplicity across a wide array of architectures.
You’ll help scale the platform model – One of your major challenges will be finding patterns and tooling to reduce duplication and improve consistency across SDKs, even as we support more platforms.
You’ll work on critical paths – Feature flag evaluations often sit in latency-sensitive code paths. You’ll help make sure our SDKs stay fast, observable, and correct.
What you'll be doing
You’ll maintain and extend PostHog’s feature flag SDKs, ensuring they are performant, idiomatic, and correct across a wide range of customer use cases. You’ll contribute to both local evaluation logic and remote integration paths, often working closely with the team that owns our flag evaluation service (written in Rust). You’ll also collaborate with language experts across PostHog to ensure high standards in SDK ergonomics and platform conventions.
A typical week might involve:
- Debugging a subtle evaluation bug in the posthog-go
SDK- Prototyping a cross-platform testing framework for SDK correctness- Implementing local evaluation in a new language SDK- Reviewing a community contribution to the posthog-node
SDK
Requirements
Experience writing idiomatic code in at least one of: Python, Go, Rust, C#, or TypeScript
Ability to reason about performance, latency, and correctness in distributed systems-
Experience designing and maintaining SDKs or libraries used by other developers
Familiarity with API design principles and developer ergonomics
Comfortable learning new languages and paradigms quickly
Nice to have
Experience with feature flag systems or configuration-as-code tools- Familiarity with local evaluation strategies and the challenges of client/server sync
Experience supporting open-source SDKs or working with external contributors
Interest in building shared tooling or infrastructure for polyglot SDK development
Understanding of observability (logging, tracing, metrics) within SDKs
We believe people from diverse backgrounds, with different identities and experiences, make our product and our company better. That’s why we dedicated a page in our handbook to diversity and inclusion. No matter your background, we'd love to hear from you! Alignment with our values is just as important as experience! 🙏
Also, if you have a disability, please let us know if there's any way we can make the interview process better for you - we're happy to accommodate!
Salary
We have a set system for compensation as part of being transparent. Salary varies based on location and level of experience.
Location
(based on market rates)Level
Step
Salary calculator
- Benchmark (United States - San Francisco, California) $243,000
- Level modifier 1
- Step modifier 0.95 - 1.04
Benefits
Generous, transparent compensation & equity
Unlimited vacation (with a minimum!)
Two meeting-free days per week
Home office
Coworking credit
Private health, dental, and vision insurance.
Training budget
Access to our Hedge House
Carbon offsetting
Pension & 401k contributions
We hire and pay locally
Company offsites
Get more details about all our benefits on the Careers page.
Your team's mission and objectives
Q2 2025 Objectives
Flag Stability, Consistency, and Resiliency
Goal: Create a highly stable, consistent, and resilient feature flag system capable of supporting 10x growth
Scale
/flags
service- Complete 100% worldwide rollout of
/flags
endpoint to all customers - Measure and validate improved query performance metrics
- Document infrastructure cost savings achieved
- Stretch: Investigate feasibility of decoupling flag evaluation from Postgres entirely
- Complete 100% worldwide rollout of
Standardize SDK Error Handling and UX
- Move more SDK functionality to the server wherever possible (reference)
- Implement unified error handling framework across all SDKs
- Create consistent fallback and default behaviors across platforms
- Ensure all SDKs utilize the latest (v2) flags response format
Enhance System Resilience
- Decouple flag service from writer database
- Deploy flags on differentiated infrastructure aligned with varying scale needs
- Implement circuit breakers for graceful degradation during upstream failures
- Establish reliability SLAs and monitoring for flag delivery
Behavioral Cohort Targeting
Goal: Enable customers to target feature flags based on user behaviors
Ship Beta Release
- Develop core behavioral targeting functionality
- Create intuitive UI for defining behavioral cohorts
- Implement backend services to process and apply cohort rules
Customer Adoption
- Identify and onboard 5-10 key customers for beta testing
- Establish success metrics and collect usage data
- Document use cases and implementation patterns
- Create support resources for customer implementation
AI IDE Integration
Goal: Streamline developer workflow with AI-powered flag implementation
Create Intelligent Code Snippets
- Develop context-aware SDK snippet generation system for feature flags
- Ensure generated code follows best practices for each language/framework
IDE Integration
- Build plugins/extensions for AI IDEs (Cursor, Windsurf, potentially our own)
- Create seamless workflow from flag creation to code implementation
- Implement AI-assisted troubleshooting for flag implementation issues
Developer Experience
- Measure time-to-implementation improvements
- Collect developer feedback on integration experience
- Iterate based on usage patterns and pain points
Interview process
We do 2-3 short interviews, then pay you to do some real-life (or close to real-life) work.
- 1
Application (You are here)
Our talent team will review your applicationWe're looking to see how your skills and experience align with our needs.
- 2
Culture interview
30-min video callOur goal is to explore your motivations to join our team, learn why you’d be a great fit, and answer questions about us.
- 3
Technical interview
45 minutes, varies by roleYou'll meet the hiring team who will evaluate skills needed to be successful in your role. No live coding.
- 4
Founder interview
30 minutesYou have reached the final boss. It's time to chat with James or Tim.
- 5
PostHog SuperDay
Paid day of workYou’ll meet a few more members of the team and work on an independent project. It's challenging, but most people say it's fun!
- 6
Offer
Pop the champagne (after you sign)If everyone is happy, we’ll make you an offer to join us - YAY!
Apply
(Now for the fun part...)
Just fill out this painless form and we'll get back to you within a few days. Thanks in advance!
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