Senior Ruby Engineer

JR United Kingdom; London; Remote; GBP 60,000 - 90,000; Full time

Job summary

Tembo is seeking a passionate Senior Ruby Engineer to join their fast-growing savings team in London. You will lead the development of innovative savings products, ensuring system reliability and contributing to a mission-driven organization focused on helping new home buyers achieve ownership.

Benefits

Enhanced parental benefits

Health insurance

Birthday day off

Abroad away day

Supportive remote-first work environment

Qualifications

• At least 5 years of professional experience in software development.
• Strong focus on Ruby on Rails.
• Experience with payment processing systems and real money transactions.

Responsibilities

• Design and develop resilient, scalable backend services in Ruby.
• Lead product feature development from ideation to deployment.
• Continuously monitor and improve system performance.

Skills

Ruby on Rails

Payment processing systems

Real money transactions

Communication

Collaboration

Job description

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Tembo is making the dream of ownership possible for a new generation of home buyers. We are a disruptive, award winning mortgage broker powered by a proprietary technology platform which aggregates every mainstream and niche lender in the UK - with the result often getting the buyer years ahead of the alternative.

We recently acquired savings company Nude Finance – now Tembo Lifetime ISA – to help us capture customers earlier in their home buying journey, nurture them through saving for a deposit and ultimately to match them with the best mortgage product to get them onto the ladder more quickly.

We’re a mission centric organization that holds our values close:

• Find a way - representing our desire to innovate and also leave no stone unturned to help find a customer a way to get on the ladder
• It's all about the people - customers, colleagues, partners - we’re all human and without them we are nothing
• If you don’t like it change it - as a startup we’re constantly listening to every source of data and evolving, every opinion counts

We are rated 4.9* on Trustpilot with every single customer review celebrated:

https://uk.trustpilot.com/review/tembomoney.com

We are well funded by Goodwater Capital, Aviva, McPike Family Global Office, Ascension, Love Ventures as well as a suite of ethical backers such as Fair by Design, Barrow Cadbury, Joseph Rowntree Foundation and Big Society Capital.

You can read more about us and our mission on our website: https://www.tembomoney.com/our-mission

About the job

Tembo is on the lookout for a passionate Senior Ruby Engineer to join the savings team. We recently launched a Cash ISA proposition to the market, powered by our proprietary savings technology and things have taken off in a big way. We have seen explosive growth and we are looking to bolster the team. You'll be working to launch new savings products to our growing number of customers, support continued scale and build tools to allow operations teams to self serve on all of their needs.

Key Responsibilities:

• Service Creation: Design and develop resilient, scalable backend services in Ruby that power critical real-money systems, ensuring reliability and consistency in high-stakes environments.
• Feature Development: Lead and contribute to the full lifecycle of product features—from ideation to deployment and maintenance—with a strong emphasis on data accuracy, security, and transactional integrity.
• Maintenance and Optimization: Continuously monitor and improve system performance, scalability, and reliability. Take ownership of system uptime and proactively mitigate bottlenecks or failures in cash reconciliation flows.
• Bug Identification and Resolution: Diagnose and resolve complex production issues in high-volume transactional environments. Implement effective monitoring and alerting to catch anomalies before they impact users.
• Code Reviews and Best Practices: Champion clean, maintainable, and well-tested Ruby code. Conduct detailed code reviews, mentor junior engineers, and foster a strong engineering culture built on quality and accountability.
• Cross-Functional Collaboration: Partner with product managers, QA, and design teams to align on priorities, define clear acceptance criteria, and deliver consistent value to the business with each release.
• Technical Investigations: Lead technical deep-dives and spike solutions to evaluate technologies, libraries, and approaches for improving system reliability, auditing, and financial reconciliation accuracy.
• Open Standards: Support our commitment to observability and open standards. Contribute to initiatives around OpenTelemetry, OpenAPI, and other tools that improve transparency and traceability across services.

About you

• At least 5 years of professional experience in software development, with a strong focus on Ruby on Rails
• Must have experience with payment processing systems and real money transactions. Experience of ledgers, holdings, valuations is highly desirable
• Communication: Excellent communication and collaboration skills, capable of working effectively in remote, cross-functional teams.
• Flexibility and adaptability: We punch above our weight, move quickly and ship often. If you thrive in a startup and want to help get us to scale-up
• Acceptance of tech debt: know when to incur technical debt to deliver business value... and when to pay it off

Why Join Tembo?

At Tembo you will do impactful work that changes people's lives. You’ll work alongside people who are motivated by the mission and desire to make home happen for an entire generation of people.

Our values flow through everything we do. You'll have the chance to make a real difference to people's lives — our TrustPilot is testament to the change we're affecting.

We offer a supportive, remote-first work environment where innovation and initiative are celebrated.

We’ve just relaunched our benefits package which includes enhanced parental benefits, health insurance, a day off for your birthday, an abroad away day (Mallorca here we come) to name just a few.

We are committed to diversity and inclusion, providing equal opportunities for all team members. Join us in our mission to deliver exceptional digital experiences and make a real difference in the technology landscape.