Technical Lead in London

About HASH

At HASH, we're building infrastructure to solve information failure and help everybody make the right decisions. Our open-source platform helps organizations turn fragmented information into typed, temporal knowledge and process graphs that support analysis, simulation, optimization and automation. We're building towards world models from a different starting point from most AI labs: explicit representations of real systems, the entities within them and the processes through which they change.

About the role

We're hiring a Tech Lead to own the architecture of almost everything built atop hgres. This includes our customer-facing frontend (the HASH "application"), integrations infrastructure, and distributed workflow execution, as well as the boundaries between these systems and hgres. This is a player-coach role. You will be the senior technical owner for a broad and interconnected surface area, while helping the engineers working within it do the best work of their careers. You might spend one day designing fault-tolerant workflow execution, another reviewing a frontend architecture or a Rust service, and another writing a specification or having a 1:1 with an engineer.

You will be accountable for the coherence, reliability and evolvability of the architecture—not for personally writing every line of code. We expect you to remain hands-on when your involvement is the highest-leverage way to establish a pattern, resolve ambiguity, unblock the team or diagnose a difficult problem. This is neither a pure engineering-management role nor an architect role detached from implementation. You should enjoy moving between systems design, code, written technical thinking and people leadership.

Requirements

• Advanced or expert proficiency in both TypeScript and Rust, with experience shipping and operating substantial production systems in each
• Advanced or expert knowledge of distributed systems, including state, consistency, concurrency, messaging, retries, idempotency, fault tolerance and observability
• A track record of owning architecture across a complex product or platform, making good boundaries and trade-offs explicit rather than allowing systems to evolve by accident
• Experience leading engineers through regular 1:1s, candid feedback, coaching and career development
• Excellent written technical communication, including the ability to produce clear specifications, RFCs and architectural decision records
• Strong judgment in design and pull-request review: able to distinguish consequential issues from preferences and raise the quality bar without becoming a bottleneck
• Experience with event-driven or workflow systems, asynchronous execution, queues and distributed coordination
• Strong understanding of modern frontend architecture and the operational systems that support a sophisticated web application
• The ability to turn product goals and incomplete requirements into tractable technical plans, expose risk early and drive decisions to closure
• High agency, intellectual honesty and a willingness to take responsibility for outcomes across team and system boundaries
• Willingness to work with us in person from our London office
• Experience with knowledge graphs, graph databases, connector or synchronization platforms, WebAssembly, or AI-assisted development is useful, but not required.

What you'll do

• Own and evolve the technical architecture of HASH outside the hGraph core, including the frontend, application services, integrations infrastructure and Flows
• Define clear interfaces between these systems and hGraph, working closely with hGraph's technical owners on cross-cutting decisions
• Design for correctness and resilience across distributed workflows, connector execution, long-running operations, retries, failures and partial state
• Write, maintain and drive alignment around technical specifications, RFCs, architectural decisions and implementation plans
• Review designs and pull requests across TypeScript, Rust and frontend code, improving both immediate implementation quality and the team's shared engineering judgment
• Establish pragmatic engineering standards for testing, reliability, security, observability, operability and maintainability
• Hold regular 1:1s with engineers, provide direct feedback and coaching, support career development and help address performance issues early
• Help engineers break ambiguous initiatives into clear milestones, owners, dependencies and risks, while preserving room for technical judgment
• Remain close to the code: prototype critical paths, establish patterns, debug difficult cross-system failures and contribute directly when doing so unlocks the team
• Improve incident response and operational learning, ensuring failures lead to better systems rather than recurring heroics
• Partner with Product and Design to shape what we build, challenge assumptions and ensure plans reflect genuine technical constraints and opportunities
• Participate in hiring and help build a team with high standards, complementary strengths and clear ownership

Why HASH

The problems are unusually rich. We are building a system that combines typed and temporal knowledge, collaborative software, integrations, AI agents and distributed workflows. Decisions made in this role will shape how those pieces fit together and how quickly the company can turn ambitious ideas into dependable products. You will have broad authority, direct access to the founders and a small team of capable engineers. There is no settled playbook to administer: you will help create the architecture, engineering practices and leadership culture required for HASH's next stage. We value people who care about the underlying problem, reason from first principles, communicate precisely and prefer durable solutions without using perfection as an excuse not to ship.

Benefits

This role pays £120,000-£175,000 base + meaningful equity.