Lovable★4.0 (43)· London

Uses Go, Rust, TypeScript; AWS, Azure, Google Cloud, Cloudflare; Kubernetes, Terraform, Temporal, OTEL, CI/CD; PostgreSQL, ClickHouse, Firestore, Spanner, BigQuery. Builds the platform for Lovable Enterprise enabling secure, cloud-agnostic deployment, defining architecture for sandboxing, networking, encryption, identity, and mentoring engineers.

Koinly★3.0 (1)· London

You will work with TypeScript on Bun, RabbitMQ, Redis, PostgreSQL, Vitest, Sentry, and Rust. The team owns the distributed data-processing backend that ingests, normalizes, and reconciles on-chain and exchange data for Koinly’s crypto tax calculation product.

You'll work with Python, NLP/LLMs, SQL/NoSQL databases, and cloud infrastructure, designing retrieval, knowledge-base, and reasoning models. You own projects end-to-end at Catapult, which builds personalised AI that understands a user's full work context across email, calendar, Slack, and other tools. No team size is given for this founding role.

Lovable★4.0 (43)· London

Build enterprise deployments using Go, Rust, and TypeScript on AWS, Azure, and Google Cloud, with Kubernetes, Terraform, and Temporal. You will build the platform that allows large customers to run Lovable securely and at scale across every major cloud provider.

You'll build backend services and microservices using Rust, Go, Python, and Java for X Money, xAI's global payment network targeting 600+ million users. The role involves designing high-scale, low-latency distributed systems for payments, fraud detection, and compliance while collaborating with iOS, Android, and web teams on full-stack features in a startup-like environment.

You’ll work with Rust or Python, designing hardened sandboxed runtimes, building CLI tools, and implementing tracing/telemetry for distributed systems. Indices is building infrastructure that turns any website into a deterministic, programmable API for AI agents.

Build and launch AI-powered products using TypeScript, React, Node.js, Rust, Azure, Docker, and LLM APIs (OpenAI, Anthropic). As the founding product engineer, you’ll own the full stack—from frontend and backend to AI workflows—and work directly with founders to shape product direction from 0 to 1.

TypeScript, Python, Rust, or C++ for a full-stack desktop application, backend for live data ingestion, and the algorithmic layer bridging research and product. This role is at a stealth-mode AI startup building a proactive AI assistant that maintains a persistent model of user work history. As a Founding Senior Engineer, you will work directly with AI researchers in a small team.

As a Senior Software Engineer at Syntasso, you'll work primarily with Golang and Kubernetes, as well as other languages like Ruby, Rust, or Python, using XP techniques such as pairing and TDD. You will design, build, and evolve Kratix, the company's open-source platform-engineering framework, and its commercial product, Syntasso Kratix Enterprise, while collaborating closely with a small, expert engineering team and customers.

Build and own the cloud infrastructure for live AI-driven trading systems, using AWS, Kubernetes, Terraform, Python, Kafka, PostgreSQL, Redis, and ClickHouse. You will design deployment pipelines, multi-region environments, and observability with Grafana, Prometheus, and Loki. This is a founding engineering role, giving you direct ownership of the platform and architecture.

TypeScript, React, Rust, Effect, HTML, Material UI, Base UI, Ariakit, and Panda. They build an open-source platform unifying structured and unstructured data to improve simulation, optimisation, and automation of real-world systems.

You will design and build the agent sandboxing platform using Go or Rust, working with containerization (Docker, Firecracker, gVisor) and virtualization technologies on Linux. The team provides a secure, high-performance code execution layer for agentic workflows deployed across internal and customer-managed environments.

You will build and own infrastructure using Linux, AWS, Terraform, CI/CD, Python (Go, Rust, C++, Java beneficial), PostgreSQL, Redis, Kafka, and ClickHouse. Your team builds real-time intelligence systems for global financial markets, combining ML, HPC, and systematic trading. This is a founding role with direct impact on live trading infrastructure.

You'll work with Rust, C, C++, Linux kernel drivers, PCIe, DMA, RISC-V assembly, custom ISAs, firmware (bare-metal/RTOS), and QEMU simulation. The company builds chips and systems to accelerate AI inference at thousands of tokens per second. This is a small cross-functional team of experienced low-level engineers.

You will work with Rust, Python, Docker, Azure/AWS, Prometheus, Grafana, and streaming databases. Helsing is a defence AI company building resilient distributed systems for high-performance machine learning inference at the tactical edge.

Proton★5.0 (1)· London

Build the Proton Drive Linux client from scratch using GTK+ or Qt, with Rust as a nice-to-have, and manage Git, CI/CD pipelines, and Linux packaging for Debian and Fedora. The Proton Drive team provides secure cloud storage and collaborative editing, and this greenfield project will create the first native Linux client.

You'll build with Python, Node, LLM APIs, and AI coding tools (Cursor, Claude), and contribute to internal frameworks for evaluation, RAG, and orchestration. Cogna's AI-powered Software Factory generates bespoke software to solve operational challenges for critical industries like energy, logistics, and manufacturing.

Encord seeks a Senior SRE Engineer to build and operate infrastructure for its AI data platform, which indexes and curates data across the ML lifecycle. You'll optimize large-scale data pipelines on GCP and AWS using Kubernetes, manage petabyte-scale storage, define SLIs/SLOs/SLAs, and instrument services with Prometheus, Grafana, OpenTelemetry, and Datadog. You'll collaborate with backend engineers (Python, Rust) and multiple squads to drive reliability, capacity planning, and observability practices as the platform scales from hundreds to thousands of AI teams.

You'll architect and build the core alert ingestion, investigation, and root cause analysis pipeline using Python and LangGraph for multi-agentic systems, with supporting infrastructure in Rust, ClickHouse, AWS/Terraform, and Next.js/TypeScript. Tracer is an open source AI SRE agent that automatically investigates production incidents across infrastructure stacks, producing grounded RCAs and fix suggestions while keeping humans in control. You'll own core architecture decisions and partner with founders to ship high-value alert types, guiding future engineers on a small, senior, execution-focused team.

Lovable★4.0 (43)· London

Lovable is an AI-powered software creation platform used by millions to build applications in any language. As a founding Forward Deployed Engineer, you'll work directly with ambitious customers using React, TypeScript, Golang, and Rust alongside LLM providers (Cloudflare, GCP, AWS) to design novel AI systems, translate real-world customer needs into product features, and shape this new function across engineering, product, and research. You'll own end-to-end projects influencing core platform direction with 5+ years full-stack experience and strong architectural thinking.

Build core exchange logic and production-grade Solana smart contracts in Rust, working on APIs, distributed systems, and low-latency backend infrastructure. The team is building a high-performance perpetual futures DEX on Solana, designing on-chain and off-chain systems for matching, margining, liquidation, and risk enforcement.

You'll develop and maintain the Agave client for the Solana blockchain using Rust or C++, focusing on performance optimization, security testing, and distributed systems reliability. Anza is an R&D lab building robust blockchain infrastructure and protocols to improve Solana's scalability and security. You'll analyze code, design benchmarking solutions, and collaborate across teams to enhance the network's robustness against emerging threats.

Encord is building a universal data layer for AI that helps teams train and run models, handling indexing, curation, annotation, and evaluation across the AI lifecycle. You'll work with PostgreSQL, ClickHouse, Python, Kubernetes, and GCP to build highly performant backend systems managing billions of structured and unstructured data items, taking end-to-end ownership of projects from architecture through deployment and impact measurement.

Encord builds a data layer for AI teams to index, curate, annotate, and evaluate data across the AI lifecycle. You'll develop TypeScript and React frontends for their editor interface, focusing on rendering high-performance 3D/4D scenes with thousands of objects across multi-modal data (images, video, audio, text, PDFs, medical images, LiDAR). Experience with WebGL, Canvas, or browser visualization is strongly preferred; Python backend and GCP/Kubernetes familiarity are pluses.

Encord seeks a frontend-leaning engineer to build complex UI and editor interfaces for their AI data platform using TypeScript and React, with strong emphasis on high-performance 3D/4D scene rendering in the browser using WebGL, Canvas, or similar technologies. You'll work on visualizing and annotating multi-modal data (images, video, audio, text, PDFs, medical images, LiDAR) as part of a small, collaborative team owning projects end-to-end from architecture through deployment.