---
title: 'Senior Software Engineer at Fonoa'
canonical: 'https://feeny.ai/job/senior-software-engineer-fonoa-zagreb-56ca7b0s69m5'
type: 'job'
last_seen: '2026-09-07'
---

# Senior Software Engineer at Fonoa

- **Company:** Fonoa
- **Location:** Zagreb, Croatia
- **Employment:** full-time
- **Work type:** hybrid
- **Posted:** 2026-08-26
- **Last confirmed live:** 2026-09-07
- **Apply:** https://jobs.ashbyhq.com/fonoa/ea772eb4-853c-4a65-a1f9-9ddcaef0aa8b

## Job description

## ABOUT ENGINEERING AT FONOA

Engineering is central to how we build the business. We focus on solving real customer problems, not just shipping features. We work in small, high-trust teams, with full ownership across the lifecycle, from design to production and beyond.

We value:

- Ownership – engineers own what they build end-to-end
- Simplicity – we break down complex problems into clear solutions
- Thinking Big - we innovate with modern technologies (LLMs, AI Agents, etc.) to solve meaningful problems
- Quality – scalable, maintainable systems are non-negotiable
- Speed & iteration – we ship fast, learn, and improve continuously
- Collaboration – we win as a team, not as individuals

## POSITION OVERVIEW

As a Staff Engineer, your role is to improve the system as a whole, both technically and organizationally.

You will work on ambiguous, high-impact problems, shape technical direction across teams, and help others build better systems. Your impact comes less from the code you write, and more from how you influence decisions, design, and execution at scale.

## WHAT YOU WILL DO

- Take ownership of complex, cross-team problems that are not clearly defined
- Define technical direction and drive system design across domains
- Identify and address systemic issues and opportunities early
- Simplify complexity through better architecture, patterns, and structure
- Improve how teams build by raising standards, tooling, and practices
- Mentor engineers and contribute to hiring and team growth
- Ensure systems are reliable, scalable, and built for long-term evolution

## WHAT GOOD LOOKS LIKE

- You focus on high-leverage problems and shape how they are approached
- You create clarity in ambiguous situations and align teams around it
- You improve not just code, but how teams design and build systems
- You make others more effective through guidance, feedback, and direction
- You operate with long-term thinking, balancing today’s needs with future scale
- You adopt emerging AI technologies and create a culture of innovation in your teams

At this level, you are expected to “make the whole system, and the people in it, better.”

## WHAT WE’RE LOOKING FOR

- Strong experience designing and operating scalable backend systems
- Proven ability to work on ambiguous, high-impact problems
- Track record of influencing technical decisions beyond your team
- Ability to balance speed, quality, and long-term maintainability
- Experience mentoring engineers and improving team practices
- Fostering a culture of curiosity and experimentation

## API DOCUMENTATION

For engineers, API design and structure are an important part of evaluating a role. You can explore our API and how we build products here: https://docs.fonoa.com/

## TECH STACK

We use these technologies today, but we don’t hire for specific tools. We care about engineers who can understand problems, make good technical decisions, and choose the right tools for the job.

- Backend: Node.js, Go
- Frontend: React, TypeScript
- Infrastructure: GCP, k8s, Terraform, Postgres

Note: If you don’t think you have the full experience we’re looking for, but you could be a fit and are willing to learn, do apply anyway! We are building a diverse and inclusive team.

As part of the recruitment process at Fonoa, we process your personal data in accordance with our Privacy Notice for Job Applicants https://www.fonoa.com/legal/privacy-notice-job-applicants. This notice explains how and why your data is collected and used, and how you can contact us if you have any concerns.

## About Fonoa

## Company Overview
- **One-liner**: Fonoa provides an AI-driven global tax automation platform that handles determination, e-invoicing, return filing, and tax ID validation for digital businesses.
- **Entity Type**: Private (most recent funding round: $110M in May 2026, total funding $195M)
- **Headquarters**: Dublin, Ireland
- **Founded**: 2019
- **Founders**: Filip Sturman (Co-founder & COO) and other co-founders formerly at Uber (names not publicly disclosed)

## Core Business
- **Primary industry/industries**: Tax compliance automation, financial technology (FinTech)
- **Target customers**: B2B – multinational digital platforms, marketplaces, SaaS businesses, and enterprises. Examples include Uber, Zoom, Booking, and Remote.com.
- **Mission or purpose statement**: “Real-time tax compliance for innovators” – to remove tax complexity so businesses can scale globally.

## Products & Services
- **Tax Engine (API)**: Deterministic tax calculation (VAT, GST, Sales Tax) across 190+ jurisdictions with sub-200ms response time. ([fonoa.com](https://www.fonoa.com/))
- **E-Invoicing**: Compliant e-invoicing with accredited government connections, ultra-low rejection rates. Powers invoicing for 1M+ sellers on leading marketplaces. ([fonoa.com](https://www.fonoa.com/))
- **Tax Return Filing**: Automated multi-country return filing with full lineage from return box to source transaction. ([fonoa.com](https://www.fonoa.com/))
- **Tax ID Validation**: Real-time validation of tax IDs in 120+ countries, with fuzzy name matching. ([fonoa.com](https://www.fonoa.com/))
- **Tax Knowledge AI**: A living global tax intelligence layer that answers complex questions with cited sources. ([fonoa.com](https://www.fonoa.com/))
- **Audit Readiness Tool**: Compresses audit readiness from weeks to minutes by providing instant access to all tax data. ([fonoa.com](https://www.fonoa.com/))

## Market Standing
- **Valuation**: Not publicly disclosed
- **Key Metric**: Total Funding – $195M (including $110M raised May 2026, which also funded the acquisition of PwC’s Global Indirect Tax Compliance platform) ([cbinsights.com](https://www.cbinsights.com/company/fonoa))
- **Notable Investors**: Index Ventures (Seed), OMERS Ventures (Series A), Coatue (Series B). Lead investor in May 2026 round not specified in search results. ([linkedin.com](https://www.linkedin.com/company/fonoa))
- **Growth Signals**:
  - 500M+ transactions processed annually.
  - Customer retention rate 97% (100% of customers who started 2025 renewed).
  - Headcount growth of +51.3% YoY (184 employees, up 79 in the last year).
  - Named to Sifted’s B2B SaaS Rising 100 for four consecutive years (2023–2026). ([fonoa.com](https://www.fonoa.com/company/about))

## Competitive Advantages
- **Single platform for the entire indirect tax lifecycle** – reduces integration complexity vs. stitching together multiple point solutions.
- **AI agents automate compliance workflows** while humans supervise, enabling audit readiness in minutes.
- **Deep government connections** for e-invoicing with near-zero rejection rates.
- **Uber pedigree** – founders built the platform based on firsthand experience scaling a global digital business.
- **Fast integration** – typical go-live in weeks or days, not months.

## Strategic Focus
- **AI-first tax platform**: Launched AI agents to autonomously execute compliance workflows, with human oversight. ([fonoa.com](https://www.fonoa.com/))
- **Post-acquisition integration**: Absorbing PwC’s global indirect tax compliance platform to expand reach and capabilities. ([fonoa.com](https://www.fonoa.com/company/about))
- **Global expansion**: Covers 190+ jurisdictions and continues to add new country support.
- **Product-led growth**: Prioritizing developer experience and API-first design to embed tax intelligence into customer products.

## Why Work Here
- **Culture & Mission**: Described as “the fastest-growing tech company in our space”; teams are encouraged to tackle complex global tax challenges with autonomy and collaboration. ([fonoa.com/company/careers](https://www.fonoa.com/company/careers))
- **Work Model**: Hybrid and remote opportunities available (depending on role); regular office meetups and team offsites. ([fonoa.com/company/careers](https://www.fonoa.com/company/careers))
- **Perks & Benefits**:
  - Competitive salary and equity stake.
  - 25 days paid time off (PTO).
  - Home office allowance for remote setup.
  - Bi-weekly team lunches.
  - Annual all-company trip (“FUNoa”) for learning and bonding.
- **Engineering & Growth**: Strong focus on engineering quality (Senior/Staff roles open in AI, frontend, data). 24% of employees are in technical departments. ([linkedin.com](https://www.linkedin.com/company/fonoa))
- **Diversity**: Operates across 18 countries with distributed teams, offering international exposure.

## Sources
1. [fonoa.com](https://www.fonoa.com/) – Product descriptions, mission, customer logos, company numbers.
2. [fonoa.com/company/about](https://www.fonoa.com/company/about) – Founding story, funding news ($110M raise + PwC acquisition), Sifted recognition.
3. [fonoa.com/company/careers](https://www.fonoa.com/company/careers) – Benefits, culture, hiring process, hybrid/remote policy.
4. [linkedin.com](https://www.linkedin.com/company/fonoa) – Employee count, revenue, funding, headcount growth, founders, exec team.
5. [cbinsights.com](https://www.cbinsights.com/company/fonoa) – Total funding amount ($195M), latest round details.

## Other roles at Fonoa

- [Junior Tax Content Analyst](https://feeny.ai/job/junior-tax-content-analyst-fonoa-zagreb-7rtfetjsncqm) — Zagreb, Croatia
- [Solutions Architect- Indirect Tax](https://feeny.ai/job/solutions-architect-indirect-tax-fonoa-new-york-s548kp6hhz9y) — New York, NY
- [Solutions Consultant, (Indirect Tax)](https://feeny.ai/job/solutions-consultant-indirect-tax-fonoa-new-york-dzfngb7jwbvj) — New York, NY
- [Procurement Manager](https://feeny.ai/job/procurement-manager-fonoa-zagreb-npyjcksx0b9x) — Zagreb, Croatia
- [Regional Sales Director](https://feeny.ai/job/regional-sales-director-fonoa-london-g7169nv4bdqy) — London, United Kingdom
- [Sales Development Representative](https://feeny.ai/job/sales-development-representative-fonoa-new-york-aqtp3rtpvznh) — New York, NY
- [Sales Development Representative](https://feeny.ai/job/sales-development-representative-fonoa-london-0a25z0w2q70j) — London, United Kingdom
- [Senior User Researcher](https://feeny.ai/job/senior-user-researcher-fonoa-london-47y4pyecpxxn) — London, United Kingdom
- [Staff Product Designer](https://feeny.ai/job/staff-product-designer-fonoa-london-v7skvrgp6vk4) — London, United Kingdom
- [Director, Sales Enablement](https://feeny.ai/job/director-sales-enablement-fonoa-new-york-6s4m9vvjgpwq) — New York, NY