Our Job Offers

Request : 

We are looking for a skilled Firmware Developer to join our R&D team in a fast-growing startup environment. In this role, you will not only develop cutting-edge firmware for embedded systems and transceivers but also contribute directly to the growth and success of the company. 

Estel develops and manufactures optical transceivers in Europe and is the first company to re-establish transceiver manufacturing on the continent. By joining our team, you will actively help bring transceiver production back to Europe, strengthening local industry and increasing European competitiveness in the global telecom and datacom markets. 

You will work across the full firmware development lifecycle - from concept and feasibility studies to design, implementation, bring-up, and validation on target hardware. This is a unique opportunity to combine hands-on technical development with strategic impact in a dynamic startup environment, where time-to-market is critically important and every contribution counts. 

Key Responsibilities : 

Participate in feasibility studies and concept development by evaluating product requirements and drafting initial FW architecture. 

Collaborate with hardware and system engineers to plan FW development and sprint planning using Scrum methodology. 

Design and implement firmware for different type of optical transceivers, including peripheral drivers, communication interfaces (I2C, SPI, UART), and device control logic. 

Implement host interfaces based on CMIS/MIS standards to ensure proper communication and interoperability with external systems. 

Develop firmware ahead of first hardware availability using emulators (e.g., QEMU) or evaluation boards to accelerate board bring-up. 

Conduct firmware bring-up and debugging on prototype modules using lab instruments such as oscilloscopes, multimeters, logic analyzers, and protocol sniffers. 

Execute firmware validation and DVT (Design Verification Test) to ensure all functional requirements are met. Implement incremental firmware features based on testing results and provide ongoing support for integration and system-level testing. 

Collaborate with cross-functional teams to review test data, troubleshoot issues, and optimize FW performance. 

Qualifications :  

Required :  

• Bachelor’s or Master’s Degree in Computer Engineering, Electrical Engineering, or similar. 
• 3-4 years of experience in embedded firmware development and testing, preferably on ARM microcontrollers, including RTOS-based systems. Programming: C/C++, Python 
• Good knowledge of I2C, SPI, UART, MDIO, J-Link and JTAG/SWD debugging. 
• Very familiar with typical FW development tools like e.g. GIT, Bitbucket, Jira, Jenkins and unit testing frameworks. 
• Experience with schematic review and basic hardware verification. 
• Familiarity with board bring-up, debugging, and integration testing on embedded hardware. 
• Good understanding of the overall development process  
• Experience of agile development methods in general and Scrum in particular 
• Strong analytical, problem-solving, and communication skills; team player with self-motivation. 

Preferred: 

• Any experience in pluggable optics development or familiarity with standard optical equipment such as OSAs, power meters, amplifiers, VOAs, and BER instruments is an advantage. 
•  Language: Swedish, Spanish, or French is an advantage

Workplace  

TechPark Malaga Spain 

Reporting

The Firmware engineer reports to the Project manager and --- CTO. 

Contact person
hr@e-s-tel.com 

Key Responsibilities

• Work with the hardware architect on: Tasks such component placements and critical design specifications.
• Engage in the concept phase: Make preliminary component placement and draft concepts in order to make sure a design is feasible.
• In the design phase: Implement the PCB layout according to the schematics using Cadence design tools and perform simulations on critical interfaces.
• Bring-up phase involves: For more advanced projects this could involve making measurements and correlating that against simulations.

Qualifications:  

Required:  

• A Master’s degree in electronics, engineering physics, or similar
• 2+ years of experience working with electronics
• Proficient in English
• Strong problem-solving skills and technical expertise
• Ability to work effectively in a fast-changing start-up environment
• Willing to learn and take on new challenges
• Swedish work permit

Preferred: 

• Experience working in a lab environment
• A thesis that includes lab/electronics design
• Proficiency in Swedish, both spoken and written
• Basic knowledge in fiber optics and network design
• A technical hobby in your spare time
• Previous working experience in the telecom field

You are Offered:

• An opportunity to join the only European transceiver manufacturer
• An exciting journey with a newly established research company in Sweden
• The opportunity to help shape the future of optical communication solutions
• A high level of expertise and the chance to learn from the best while working on bleeding edge technologies
• A dynamic work environment where things happen quickly and you get to do a lot

Workplace: 

This position is based in our R&D center in Stockholm, Sweden. 

Estel Sweden AB, C/O CONVENDUM Vasagatan 14A 172 61 Sundbyberg, Sweden

Request:

Estel is now looking for a Mechanics Development Engineer. The primary focus will be on mechanical design of our pluggable transceivers but may also include thermal management simulations. The role spans from early concept development to design for automated manufacturing and assembly in volume production. You will get to work on bleeding edge technologies and make sure that the design in the end meets all the requirements with respect to size, price and performance. Your tasks will include working closely with the HW architect and electronics designers to make sure your design is optimized for the application.

Key Responsibilities:

• Be our driving force in communication with our mechanics vendors.
• 
  
• Engage early in the concept phase: Identify and shortlist components and vendors. Make preliminary mechanical designs, working iteratively with the HW Architect and layout engineers towards a viable product.
• 
  
• In the design phase: Ensuring that the  module enclosure complies with applicable standards and multisource agreements, while the inside is optimized with respect to real estate usage, robustness, cost and performance. Implement the mechanical design using Solid Works. Make Tolerance stackup analysis (e.g. Monte Carlo simulations,  3 Sigma). Make mechanical drawings. Work with the mechanical vendors as needed. 
• 
  
• Bring-up / Design Verification Test phase: Mechanical design verification test (MDVT) of the complete product. Produce comprehensive MDVT reports. 

Qualifications:  

Required Competence:   

• 4+ years of experience working in SolidWorks or similar 3D CAD programs 
• Experience of mechanical designs of telecom / datacom or similar products 
• Strong problem-solving skills and technical expertise 
• Ability to work effectively in a fast-changing start-up environment 
• Self-motivated Teamworker 
• Willing to learn and take on new challenges 
• M.Sc or B.Sc degree with relevant direction 
• Strong documentation skills 
• Proficient in English 
• Valid work permit within the European Union 

Preferred Experience and Competence on:  

• Machined metal / CNC milling Diecasting of metal for housing of electronics products 
• Sheet metal design 
• Thermal management/Simulation
•  Rapid prototyping.Hands-on in the lab 
• FMEA methodology 
• FEA / FEM simulations 
• PDM systems (e.g. 3DExperience Solidworks, Windchill) 
• Mechanical design for embedded (non-consumer) electronics 
• Design for EMC/EMI compliance 
• Proficiency in Swedish, spoken and written 
• Basic knowledge of fiber optics and network design 
• Previous working experience in the telecom field 

You are Offered: 

• An opportunity to join the only European transceiver manufacturer. 
• An exciting journey with a newly established research company in Sweden.
• The opportunity to help shape the future of optical communication solutions.
• A high level of expertise and the chance to learn from the best while working on bleeding edge technologies.
• A dynamic work environment where things happen quickly and you get to do a lot.

Workplace: 

This position is based in our R&D center in Stockholm, Sweden. 

Estel Sweden AB, C/O CONVENDUM Vasagatan 14A 172 61 Sundbyberg, Sweden

Request :

Estel is now looking for an NPI Engineer for our Production line in Chastrès, Belgium. The NPI Engineer will support the development and industrialization of advanced optical transceiver modules. The ideal candidate will have strong experience in mechanical design, optical module packaging, assembly processes, and NPI execution. Experience of FAU (Fiber Array Unit) machines for optical alignment, fibre attach, and precision assembly is a merit. 

This role is highly cross-functional, working closely with R&D, optics, electronics, reliability, and manufacturing teams to bring optical transceiver designs from prototype to mass production. 

Key Responsibilities :

Mechanical & Packaging Engineering 

Perform geometric, tolerance analysis, and material selection for precision assembly. 

Collaborate with electrical, optical and thermal engineers to ensure robust system integration. 

Optical Module Assembly & Process Development 

Develop and qualify assembly processes such as: 

• Fiber attach and optical alignment (active and passive) 
• FAU, PM fibre, PIC, glass interposer handling, placement, and bonding 
• Soldering, epoxy dispense/cure, laser welding, cleaning 
• Component assembly such as lens, isolator, connector mating, hermetic sealing. 

Define assembly jigs, fixtures, and tooling for NPI and mass production. 

Conduct process capability studies and drive DFM/DFA improvements. 

NPI Execution 

Lead NPI builds for transceiver modules, from EVT/DVT into pilot and MP. 

Operate, configure, and troubleshoot FAU NPI machines for test runs and engineering builds. 

Develop SOPs, WI, BOMs, ECNs, and process documents. 

Support FA (Failure Analysis) and root cause investigations for yield and performance issues. 

Interface with CM partners to ensure smooth production transfer. 

FAU NPI Machine Operation & Optimization 

Operate FAU automated equipment for: 

• Fiber alignment 
• Fiber attach (UV/thermal bonding) 
• Optical coupling validation 

Optimize machine recipes, bonding parameters, and alignment algorithms. 

Monitor machine performance, diagnose issues, and work with vendors for maintenance or upgrades. 

Train technicians and operators on best practices for FAU-based assembly processes. 

Qualifications:  

Required :  

• Master's degree in mechanical engineering, Opto-Mechanics, Mechatronics, or related field. 
• 3+ years’ experience in photonics assembly, packaging, opto-mechanical design, or NPI. 
• Hands-on experience operating or developing processes on FAU / fiber attach NPI machines. 
• Strong CAD experience (SolidWorks, Creo, or equivalent). 
• Familiarity with GD&T, tolerance stack-up, precision mechanics, and optical coupling principles. 
• Working knowledge of DFM, DFA, SPC, and NPI process flows. 
• Language: English on C1 Advanced to C2 Proficient level 

Preferred : 

• Experience with PIC, Optical component packaging, micro-optics, active alignment, and optical test. 
• Knowledge of QSFP, OSFP, SFP, CFP, or other telecom/datacom multisource agreement form factors. 
• Experience with high-volume optical component manufacturing. 
• Driver License. 

Workplaces 

This position is be based in our headquarter in Walcourt, Belgium. 

4 Allée des Plantains, 5650 Chastrès Belgium 

Reporting 

The NPI engineer reports to the Production Manager and --- CTO. 

Contact person 
hr@e-s-tel.com 

Request :

Estel is now looking for a Sales Director for Telecom Operators responsible for leading and expanding strategic sales activities with global and regional telecom carriers (Tier 1, Tier 2, and alternative operators). This role combines deep market understanding of optical networking with strong commercial leadership to drive revenue growth, secure long-term partnerships, and position the company as a preferred supplier of optical transceiver solutions.

The Sales Director will manage key accounts, develop strategic sales plans, coordinate cross-functional teams, and ensure successful execution of high-value commercial engagements.

This role is highly cross-functional, working closely with R&D, optics, electronics, reliability, and manufacturing teams to bring optical transceiver designs from prototype to mass production. 

Key Responsibilities :

Strategic Sales Leadership

• Develop and execute a comprehensive sales strategy targeting telecom operators globally or regionally.

• Identify growth opportunities in 5G, FTTH, metro/core networks, data transport, coherent optics, and emerging technologies.

• Lead full-cycle sales activities from opportunity identification to contract negotiation and closure.

Account Management & Customer Development

• Own executive-level relationships with telecom operators, including procurement, engineering, and network strategy teams.

• Build a multi-year account plan to increase share of wallet and strengthen vendor positioning.

• Gather customer requirements and influence product roadmaps in alignment with operator needs.

Revenue & Pipeline Growth

• Drive sales performance to meet or exceed revenue, margin, and volume targets.

• Manage accurate forecasting, funnel management, and quarterly business reviews.

• Lead the preparation of commercial proposals, RFQs/RFPs responses, and long-term supply agreements.

Cross-Functional Collaboration

• Work closely with product management, engineering, marketing, operations, and executive leadership.

• Translate customer requirements into clear technical and operational actions.

• Coordinate with supply chain teams to optimize allocation, lead times, and delivery performance.

Market & Competitive Intelligence

• Monitor market trends such as coherent evolution, 400G/800G transitions, pluggable optics, disaggregation, and ROADM architectures.

• Track competitor positioning, pricing strategies, and technology roadmaps.

• Provide insights to support strategic decisions and product differentiation.

Qualifications & Experience

Required

• 10+ years of sales experience in telecom, optical networking, or related telecom hardware sectors.

• Proven success managing large accounts in Tier 1/Tier 2 operators.

• Deep knowledge of optical transceivers, DWDM systems, coherent optics, switching/routing ecosystems, and operator procurement cycles.

• Strong negotiation skills and ability to close multi-million-dollar contracts.

• Excellent communication skills with the ability to manage C-level relationships.

Preferred

• Experience in an optical module or photonics manufacturing company.

• Understanding of technical standards (IEEE, ITU-T, OIF) and optical module form factors (SFP/SFP+, QSFP28/56/112/DD, CFP/CFP2/CFP4, OSFP).

• Familiarity with global telecom infrastructure trends: 5G transport, broadband rollout, open/ disaggregated optical networks.

• MBA or advanced business/technical degree.

Workplaces 

Onsite or remote 

Reporting 

The Sales Director reports to the Sales Manager and C-level

Contact person 
hr@e-s-tel.com