Backend Engineer

Senior Backend Engineer

Junior

👶 ABOUT JUNIOR We're building cutting-edge LLM-powered tools that supercharge investment research for the world's most demanding deal teams. Our clients include several of the top 10 global private equity firms, Big 4 professional services firms, and leading consulting practices: organisations responsible for deploying billions of dollars annually. We're a profitable, bootstrapped company with a growing team of ~43 people based in London and New York. We 10x'd our revenue in 2025 and are on track to grow 2-3x again this year. Junior saves clients an average of 10 hours per week, and we're expanding fast into new verticals including investment banking, hedge funds, and research firms. You can read more about the company mission & values here. 💡 ROLE DESCRIPTION As a Backend Engineer, you’ll help build and scale the systems that power our AI-driven research platform. This is a systems-level role - ideal for engineers who love thinking about data flows, orchestration, and performance across complex distributed systems. You'll have the unique opportunity to: * Ship quickly * Architect and scale backend systems that support high-throughput LLM interactions, vector search, and multi-agent orchestration. * Stitch together AI infrastructure across model providers, data stores, and internal APIs to create cohesive, performant systems. * Own reliability and observability, helping us evolve our database (Postgres / ClickHouse) and job orchestration systems. * Prototype new backend capabilities (retrieval pipelines, caching layers, async task queues) that let us build faster and smarter. * Shape our engineering culture 🔥 ABOUT YOU We're looking for product-minded backend engineers who: * Are based in NYC and excited to work 5 days a week in person * Are excited by the intersection of AI infrastructure, financial systems, and backend engineering * Have experience owning backend projects end-to-end — from architecture through to production * Are strong in Python and TypeScript * Have worked with PostgreSQL and care about data modelling, reliability, and system design * Are comfortable building APIs, internal tools, workflows, and infrastructure that support real customers * Are eager to contribute to product decisions, not just execute tickets * Feel like you are never building fast enough Bonus points for experience working on: * Billing, payments, usage-based pricing, or financial workflows * Internal infrastructure / dev tools at startups * Data pipelines, workflow orchestration, or event-driven systems * Retrieval, embeddings, or prompt orchestration 🌵 BENEFITS All the usual benefits (competitive pay and equity, private healthcare etc). Unusual benefits: * Gym membership * In-office cook * Summers working in Greece by the beach 📩 HOW TO APPLY If you're excited about the opportunity to drive innovation at Junior, we'd love to hear from you! Email us at careers@myjunior.ai with your resume and a brief introduction. We can't wait to meet you! 🙌

Staff Backend Engineer

Superstate

Tired of the inefficiencies and complexities of traditional finance? We are too. At Superstate, we create investment products that benefit from the speed, programmability, and compliance advantages of blockchain tokenization. As an engineer at Superstate, you'll play a pivotal role in shaping the future of tokenized assets. You'll work on blockchain-integrated systems that allow investors to self-custody financial assets, and design the systems, APIs, and infrastructure to make finance itself more efficient.

Staff Software Engineer, Backend (Communications Platform)

Squarespace

Squarespace is looking for a Backend Staff Software Engineer to lead the technical direction of our Communications Platform team. The Communications Platform is a critical engine powering customer engagement across Squarespace — providing internal teams with a scalable, reliable, and secure infrastructure for delivering communications via email, push notifications and in-product messaging. The team owns multiple interconnected production platforms that collectively send over 1.75+ million notifications per day, strategic initiatives including platform modernization, In-Product Placements, and multi-channel communication capabilities. In this role, you’ll serve as the senior technical voice for the team — driving architecture, shaping roadmap execution, and elevating the engineering quality of a small but high-impact team. This is a hands-on role with real technical depth, paired with broad cross-functional influence. This is a hybrid role based in our NYC office (3 days per week), reporting to the Engineering Manager of Communications Platform. YOU’LL GET TO… * Drive the architecture, design, and implementation of the Communications Platform’s platforms — including Email Delivery, In-Product Notifications and Push Notifications. * Define and own the technical strategy for platform modernization, reliability hardening, and engineering standards across backend services. * Provide hands-on technical leadership and mentorship to a team of backend and frontend engineers, helping them grow in system design, decision-making, and ownership. * Write high-quality Java code and stay close to execution — leading design reviews, code reviews, and architectural decisions that raise the bar across the codebase. * Proactively identify and address systemic risks in performance, reliability, security, and operability before they become incidents. * Serve as a key technical partner on cross-team and company-wide architecture initiatives. * Balance short-term delivery with long-term platform health, communicating tradeoffs clearly to stakeholders and leadership. WHO WE’RE LOOKING FOR * 10+ years of backend engineering experience, with significant time building and operating large-scale, customer-facing systems. * Deep expertise in Java and backend service development, including APIs, async processing, messaging systems (ex: Kafka), and data stores (ex: MongoDB, CockroachDB). * Strong experience with distributed systems in production — including reliability, scaling, failure modes, and observability. * A proven track record of technical leadership at the Staff or Senior-plus level, influencing architecture across multiple teams or services. * Experience evolving existing systems — modernizing legacy platforms, simplifying complexity, and strengthening reliability without unnecessary rewrites. * Experience operating within platform engineering contexts, where your customers are internal or external product teams and the quality of your APIs and abstractions directly shapes their velocity. * A strong understanding of multi-channel communication infrastructure (email delivery, push, in-product notifications) is a meaningful plus. * The ability to communicate complex technical concepts clearly to both technical and non-technical partners. * A mindset oriented toward mentorship, collaboration, and inclusive technical leadership. TECHNOLOGIES YOU'LL WORK WITH * Java, Spring, Kafka, MongoDB, CockroachDB, Kubernetes, GCP. * The team actively uses Claude Code, Cursor and GitHub Copilot to accelerate development and code review. BENEFITS & PERKS * A choice between medical plans with an option for 100% covered premiums  * Fertility and adoption benefits * Access to supplemental insurance plans for additional coverage * Headspace mindfulness app subscription * Global Employee Assistance Program * Retirement benefits with employer match * Flexible paid time off * 12 weeks paid parental leave and family care leave * Pretax commuter benefit * Education reimbursement * Employee donation match to community organizations * 7 Global Employee Resource Groups (ERGs) * Dog-friendly workplace * Free lunch and snacks * Private rooftop * Hack week twice per year CASH COMPENSATION RANGE: $185,500 - $299,000 USD The base salary for this position will vary based on job-related criteria including relevant skills, experience, and location, among other factors. In addition to the cash compensation above (which includes base salary and, where applicable for eligible roles, may include overtime pay), Squarespace employees are eligible to be granted an option to purchase our common stock. Sales positions generally offer a competitive On Target Earnings (OTE) incentive structure in addition to base salary. ABOUT SQUARESPACE Squarespace is a design-driven platform helping entrepreneurs build brands and businesses online. We empower millions of customers in more than 200 countries and territories with all the tools they need to create an online presence, build an audience, monetize, and scale their business. Our suite of products range from websites, domains, ecommerce, and marketing tools, as well as tools for scheduling with Acuity and creating and managing social media presence with Bio Sites and Unfold. Our team of more than 1,700 is headquartered in New York City, with offices in Dublin, Ireland, and Aveiro, Portugal. For more information about our company, visit https://www.squarespace.com/about/careers. OUR COMMITMENT  Today, more than a million people around the globe use Squarespace to share different perspectives and experiences with the world. Not only do we embrace and celebrate the diversity of our customers, but we also work toward the same in our employees. At Squarespace, we are committed to equal employment opportunity regardless of race, color, ethnicity, ancestry, religion, national origin, gender, sex, gender identity or expression, sexual orientation, age, citizenship, marital or parental status, disability, veteran status, or other class protected by applicable law. We are proud to be an equal opportunity workplace. #LI-Hybrid Thank you in advance for providing the following details about your work history from your resume! This helps us ensure that your candidate information is accurate and consistent during the hiring process.   Squarespace will never solicit your personal banking information or ask you to transfer money in connection with a job offer or interview. We also will not reach out to you via phone or SMS without your permission or knowledge.   If you plan to use AI in any capacity during your candidate journey, please review our Candidate AI Policy.