Staff Backend Engineer - Search Features & APIs (SABR)

About us

Launched in 2019, Constructor is an AI-first e-commerce search and discovery platform that helps shoppers find the right products at the right time and enables leading global e-commerce brands to drive meaningful revenue and conversion gains.

About the team

The SABR team owns the top layer of request processing for product discovery. We own the service that first receives product discovery requests (autocomplete, search, browse & recommendations) & executes the entire business logic that drives product discovery. That service also functions as a gateway to parse incoming user requests, orchestrate calls across the internal services that do the ranking and retrieval, interpret their responses, and assemble the final response the customer sees.

We also own the public configuration APIs customers use to control how discovery behaves, and the MCP layer that exposes all of it to AI agents.

Our team owns both platform & product components: Because of the positioning of our services, we take part in every architectural decision of our core product offering. At the same time, our goals are heavily influenced by direct customer feedback, because all product discovery-related features are either implemented in or integrated with our services.

All of our services are public APIs, so interface design and backward compatibility are a constant part of the job. But most of our attention goes to keeping them fast and up: we serve up to 15k RPS, fan out to many internal services on every request, and are expected to stay available and degrade gracefully when any of them fails or slows down.

The work is distributed systems in practice rather than in theory: request orchestration, failure isolation, caching, latency budgets, capacity planning, and the observability to know what is actually happening in production. The team is small enough that engineers own problems end to end, from design through on-call.

About you

You're a staff-level engineer who wants to own systems, not tickets. You've built high-traffic, low-latency Python services and carried the pager for them. You think in trade-offs: latency versus cost, flexibility versus a public API that customers can't afford to see break, the fix that ships this week versus the architecture that has to last two years.

You can lead work that spans several engineers and several quarters, you enjoy mentoring others, and you're fine when a problem shows up half-defined. You don't mind being the one who reads the spec for some unfamiliar protocol, works out how it fits, and designs an integration that holds up at scale. You change your mind when someone has a better argument, you make the people around you better, and you still care about your code long after it merges.

What you will do

• Own the technical direction of one or more of our services - architecture, performance, and reliability.
• Lead design of new systems and public APIs, and the evolution of existing ones as traffic and feature scope grow.
• Raise the engineering bar through design and code review, and mentor mid and senior engineers into owning bigger scopes.
• Partner with product, other engineering teams, and solutions/support to shape what we build and to represent search constraints and trade-offs honestly.
• Take part in on-call for the systems you own, and lead incident response and follow-through when things break.

What we are looking for

Technical

• Substantial experience building and operating high-traffic, low-latency backend services in production.
• Extensive Python knowledge (our primary language).
• Experience with observability and performance work in live systems.
• Experience designing and evolving public APIs that external customers depend on.
• Experience designing & implementing scalable service-oriented architectures.

Beyond the code

• Track record of leading projects that span multiple engineers and quarters.
• Influence without authority, and willingness to change your position when someone has a better argument.
• Clear written communication - design docs, RFCs, postmortems.
• Good judgment about trade-offs and scope.
• Comfort with ambiguity and loosely defined problems.
• Ownership that extends past merge, to how the system behaves in production.

Nice to have

• Experience with AWS
• Background in search, ranking, information retrieval, or e-commerce product discovery.
• Exposure to AI/LLM-facing infrastructure (MCP, agent tooling, or similar).

Benefits

🏝️ Unlimited vacation time - we strongly encourage all of our employees take at least 3 weeks per year

💻 Apple laptops provided for new employees

🧑‍🎓 Training and development budget for every employee, refreshed each year

👪 Maternity & Paternity leave for qualified employees

🧠 Work with smart people who will help you grow and make a meaningful impact

💵 Base salary: $110k–$130k USD, depending on knowledge, skills, experience, and interview results

📈 Stock options - offered in addition to the base salary

🎉 Regular team offsites to connect and collaborate