Senior Back End Engineer (Integrations) at Abacum

About Abacum Abacum is the leading Business Planning solution for finance teams to drive performance. By automating reporting, enabling collaboration, and simplifying planning and forecasting, we help finance teams shift from number crunching to driving strategic decisions. Founded in 2020 by two former CFOs, we’ve grown into a global team of 100+ people across 30+ nationalities. Headquartered in New York, we have offices in London and Barcelona. We’re trusted by industry leaders such as Dish Networks, Strava, BetterUp, Kajabi, JG Wentworth, Abridge, Cortex, and hundreds more. We have raised over $100m, closing in June 2025 our $60M Series B, led by Scale Venture Partners, with the strong participation of Cathay Innovation, Y Combinator, Atomico, Creandum, and angel operators from Adyen, Zapier, and Twitch. Our mission is ambitious and we can’t do it alone - join Abacum as we build the future of Business Planning! We are looking for... … talented engineers who possess infinite curiosity to solve complex problems not existing in the market (multi dimensional real time calculations engine), are excited to become part of our early story and help create groundbreaking technology that truly improves how finance teams work and collaborate. Creating an amazing opportunity to code in an extremely agile environment, with a direct long-term impact on our product and users. Our ideal candidate has a strong sense of ownership in their work, is willing to learn quickly, committed to shaping our technical design and engineering culture. Being a Software Engineer at Abacum means... - Collaborate closely with engineers, product designers, and product to perform experiments and test new ideas - Build performant, design-centric, reusable and usable interfaces that solve complex needs. Such as customisation possibilities for our users, complex data visualisations (graphs, charts, etc...), delightful components that provide the best platform experience - Drive user defined data modeling and performance, providing the user with customization possibilities through reusable building blocks: models, variables, formulas, … - Take operational responsibility for the components that you write - Work in an environment that supports your individual growth by providing you with challenging tasks and projects to solve and the freedom to acquire new skills in hack time - Work with product and our operations team to incorporate customer feedback in order to constantly improve our product - Scale our complex data and calculations platform for a fast growing number, size and complexity of clients What You’ll Do as a Senior Back End in the integrations team: - Move fluently across multiple programming languages and ecosystems beyond our core stack (not limited to Python or Django) to read, adapt, and extend integration-specific code such as ERP scripting frameworks (e.g. SuiteScript), native app extensions for accounting and finance platforms, and third-party vendor SDKs. - Work confidently with a wide range of authentication and identity flows, including OAuth 2.0 / OIDC, SSO providers (Microsoft Entra ID, Okta, Google Workspace), SAML, and service-to-service authentication. Comfortable managing different token types (access, refresh, JWT, API keys), handling token lifecycles, and applying secure communication protocols (TLS/HTTPS, signed requests, secret management) across all integrations. - Lead the design and development of Abacum's integrations platform for ingesting, normalizing, and annotating business data. - Build and scale bidirectional integrations with billing, accounting, ERP, commerce, and HRIS platforms. - Architect low-code/no-code tools (e.g. connector builder, declarative DSLs, LLM-assisted workflows), and choose between integration strategies (unified API, in-house, contractors) to accelerate integration development and maintenance. - Ensure integrations are secure, resilient, and performant at scale, supporting high-volume financial and transactional data. - Collaborate closely with product, design, financial experts, and customers to translate complex, ambiguous workflows into intuitive software experiences. - Establish technical standards, and guide architecture for integrations and data-heavy systems. Your Experience - 7+ years of experience, at least 2+ of which are on integrations roles - Strong background in building integrations for data-heavy use cases - Hands-on depth in Python and modern backend systems - Experience architecting or working on integrations platforms, data platforms, or similar large-scale API ecosystems. - Curiosity and persistence in tackling ambiguous, high-stakes technical problems like low-code builder design, LLM-assisted workflows, and data enrichment - Pragmatic judgment: know when to ship quickly vs. when to invest in foundational architecture. Benefits - Competitive compensation including equity package - Competitive vacation policy - Access to Meditopia - Hybrid working model and flexible working hours - Personal development including language courses Our Values Customer Obsession: We share the understanding that Abacum's sole purpose is to create value for customers and relentlessly deploy all creativity and energy to that end. Audacious Ambition: We dream big and embrace discomfort. We assume risks, make on-time mistakes and learn how to methodically accomplish our goals. Good People: We are self-reflective and praise diversity of thought. We don't justify the end with the means and know where to draw the line. We have fun every day. Tough Love: We truly care for everyone in the team and embrace honest feedback and radical candor as ways to genuinely help each other. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender perception or identity, national origin, age, marital status, protected veteran status, or disability status.