Software Engineer – AWS - LocalStack

About LocalStack

LocalStack is the leading local cloud development platform. We make it easier, faster, and less expensive for software teams to ship reliable, high-quality applications to the cloud. Our platform provides secure local sandboxes that simulate cloud environments, enabling AI agents and software developers to find and fix risks faster and more effectively.

Our customer base ranges from SMBs to Global Fortune 500 companies, including NASA, IBM, Workday, Comcast, Apple, and many more. We are sustainably growing our globally distributed engineering team.

About the Role

As a Software Engineer on the AWS Emulator team, you'll help expand and harden LocalStack's AWS emulator by taking ownership of individual services and making them behave as closely as possible to real AWS.

The challenge is genuinely unusual: you'll reimplement cloud services that you can only observe from the outside, matching AWS behavior including edge cases and undocumented details. You'll have end-to-end ownership of your services, from investigating behavior through implementation, testing, and ongoing improvements.

AI is a core part of how the team works. You'll use modern AI coding and agentic tools to make development more efficient while maintaining high quality and reliability.

What You Will Be Working On

• Internalize services off moto: Independently take AWS services from moto-backed to fully first-party implementations, owning store design for persistence and full API operation coverage.
• Close parity gaps: Raise snapshot-test coverage against real AWS for the documented API surface for owned services with a measurable reduction in parity defects.
• Own services end-to-end: Act as first responder for your services, triaging and resolving customer-reported parity bugs within 5 days median.
• Raise the testing floor: Contribute reusable test infrastructure, conformance harnesses, and snapshot tooling.
• Grow in scope: Progress to independently scoping and sequencing service internalizations from API-documentation analysis to shipped provider.

Experience We Expect You to Bring

• 3+ years of professional software engineering experience with strong fundamentals (language-agnostic; prior Python is not required).
• Experience working from a written specification against a system you cannot see inside (public APIs, protocols, wire formats, parsers, compilers, SDKs, emulators, or reverse-engineering).
• A strong testing mindset, using tests as a tool for understanding and designing systems.
• Hands-on experience with AI coding and agentic development tools to build and ship real software.
• Fast learning and strong problem-solving skills with incomplete information.

Strong Plus

• Open-source contribution experience.
• Experience working with AWS at application or platform level.
• Experience with distributed systems, storage, or protocol conformance.

Benefits

• Fully remote work environment
• Competitive salary
• Yearly bonus
• Annual company retreat
• 2 extra company-wide holidays
• Inclusive workplace culture with community guilds and online events