Senior Software Engineer, Optimization Service

Hybrid, Bucharest, Romania
JOB OVERVIEW
As a
Senior Software Engineer
on the
Schedule Optimization
team, you'll play a key role in building and scaling Legion's intelligent scheduling that implements sophisticated scheduling and optimization algorithms. You will use your expertise in linear algebra, optimization modeling (including MILP/LP), and production-grade Java systems to deliver solutions that balance business requirements, compliance rules, and employee preferences at scale.

In this role, you'll take ownership of designing, implementing, and productionizing optimization services and integrating them into Legion's backend architecture (leveraging Spring Boot, Hibernate, MySQL, etc.). You'll help shape how millions of hourly workers get scheduled more fairly and efficiently, thereby helping realize Legion's mission.

RESPONSIBILITIES AND DUTIES

• Design, develop, and optimize scalable optimization algorithms for workforce scheduling and labor planning.
• Formulate and implement Mixed Integer Linear Programming (MILP) and Linear Programming (LP) models using Gurobi (or equivalent solver).
• Translate complex business rules (labor laws, staffing constraints, employee skills/preferences) into mathematical formulations and solve them in production.
• Write high-quality, secure, efficient enterprise-grade Java code, integrated with the backend stack (Spring Boot, Hibernate, MySQL).
• Optimize runtime performance, throughput, and scalability of optimization services to support large enterprises.
• Integrate optimization services into APIs and production systems, working cross-functionally with Data Science, Product, and Platform Engineering teams.
• Participate in on-call rotations and monitor/maintain production systems for reliability and performance.
• Mentor junior engineers and contribute to best practices in optimization modeling, software design, and operations.

REQUIRED SKILLS AND QUALIFICATIONS

• Master's degree or PhD in Applied Mathematics, Operations Research, or a related quantitative field.
• 5–8 years of professional software engineering experience, with strong Java development expertise.
• Solid understanding of mathematical optimization concepts including linear programming and mixed integer programming.
• 5+ years of experience writing enterprise-quality Java code, including secure, efficient, scalable implementations.
• Strong understanding of distributed systems, APIs, data processing, and performance/scalability tradeoffs.
• Excellent communication skills and ability to collaborate across teams and mentor others.

PREFERRED QUALIFICATIONS AND SKILLS

• Experience with Gurobi or equivalent optimization solvers (CPLEX, OR-Tools, SCIP).
• Experience in workforce scheduling, shift optimization, traffic optimization or other labor/resource scheduling domains.
• Familiarity with constraint programming (CP), metaheuristics, or stochastic optimization.
• Ability to operate in fast-paced, resource-constrained environments.

ABOUT LEGION
Join Legion's mission to turn hourly jobs into good jobs. We're a mission-driven team seeking exceptional talent to propel this vision. Embrace a culture that's collaborative, fast-paced, and entrepreneurial. With us, you'll grow your skills, work closely with experienced executives, and contribute significantly to our mission.Our award-winning AI-native workforce management platform is intelligent, automated, and employee-centric and proven to deliver 13x ROI. We help labor-intensive organizations maximize labor efficiency and employee engagement simultaneously. Legion has earned recognition for its innovation, including spots on the Inc. 5000 list, Forbes' Next Billion Dollar Startups, and awards for our AI technology. Backed by leading investors such as Norwest Venture Partners, Stripes, First Round Capital, XYZ Ventures, Webb Investment Network, Workday Ventures, and NTT DOCOMO Ventures, we're making real change.

If you're ready to make an impact and grow your career, Legion is where you belong. Join us in making hourly work rewarding and fulfilling.

BACKGROUND AND OPPORTUNITY
There are almost 75 million hourly workers in the United States, representing more than half of the entire workforce. Historically, managing hourly employees has been difficult due to high attrition (average of 60%) and high replacement costs (average of $3,200 per employee in retail). The ongoing labor shortage and competition from the gig economy, make it more difficult to attract and retain hourly employees. The top reasons hourly employees leave their jobs are a lack of schedule empowerment, poor communication with employers, and an inability to get paid early. Gen Z and the millennial workforce demand gig-like flexibility, modern technology, and compelling work options. Legion's mission is to turn hourly jobs into good jobs, serving the hourly workers who make up the majority of the US workforce. We believe in empowering employees and helping employers be efficient and innovative by enabling intelligent automation powered by Legion's Workforce Management platform to optimize labor efficiency and enhance the employee experience simultaneously.

Legion WFM was built for the cloud with AI at the core and is designed to handle the complexity of modern businesses and meet the needs of today's hourly employees. Our team is composed of dedicated individuals from all backgrounds and experiences, globally distributed across all time zones.

For more information, visit

COMPENSATION & BENEFITS
At Legion, we offer competitive compensation and benefits packages to all employees. As a fully remote employer, pay for positions is determined using local, national, and industry-specific survey data.

We strive to make competitive offers allowing employees room for future growth. Salaries will be based on the applicant's location, level of experience, education, and specialized knowledge and skills. Additionally, we consider the external market rate, the amount we have budgeted internally, and internal equity within the company for the same position.

Benefits include, but are not limited to:

• Health Benefits
• Paid Time Off and Paid Holidays
• Parental Leave
• Equity
• Monthly Wellness Reimbursement
• Monthly Lunch on Legion

EQUAL EMPLOYMENT OPPORTUNITY
Legion Technologies is proud to be an equal opportunity employer and is committed to maintaining a diverse and inclusive work environment. All qualified applicants will be considered for employment without regard to race, color, religion, sex, age, disability, marital status, familial status, sexual orientation, pregnancy, genetic information, gender identity, gender expression, national origin, ancestry, citizenship status, veteran status, and any other legally protected status under federal, state, or local anti-discrimination laws.

DISABILITY ACCOMMODATION
For individuals with disabilities who need additional assistance at any point in the application and interview process, please email

Legion is an equal opportunity employer. All applicants will be considered for employment without attention to race, religion, color, sex, sexual orientation, gender identity, age, national origin, veteran, disability status, or any other basis covered by appropriate law.
How We Determine What We Pay
As a global employer, Legion determines pay for positions using local, national, and industry-specific survey data. We evaluate external equity and the cost of labor/prevailing wage index in the relative marketplace for jobs directly comparable to jobs within our company. Our posted salary range is based on national data and may be refined for a candidate's region/town/cost of living. For new hires, we strive to make competitive offers allowing the new employee room for future growth. Salaries will be based on the applicant's location, level of experience, education, and specialized knowledge and skills. Additionally, we consider the external market rate, the amount we have budgeted internally, and internal equity within the company for the same position. An employee/candidate with a stronger skill set will receive higher pay.
Job Applicant Privacy Policy

This Job Applicant Privacy Policy ("
Policy
") describes how Legion Technologies, Inc. ("
Legion
", "
we
", "
us
" and "
our
") collects, uses, and discloses "personal information" as defined under California law from and about job applicants who are residents of California.

This Policy does not apply to our handling of data gathered about you in your role as a user of our consumer-facing services. When you interact with us as in that role, the Legion Privacy Policy applies.

• Types of Personal Information We Handle

We collect, store, and use various types of personal information through the application and recruitment process. We collect such information either directly from you or (where applicable) from another person or entity, such as an employment agency or consultancy, background check provider, or other referral sources. This information includes:

• Identification and contact information, and related identifiers
  such as full name, date and place of birth, citizenship and permanent residence, home and business addresses, telephone numbers, email addresses, and such information about your beneficiaries or emergency contacts.

• Professional or employment-related information,
  including:

• Recruitment, employment, or engagement information
  such as application forms and information included in a resume, cover letter, or otherwise provided through any application or engagement process; and copies of identification documents, such as driver's licenses, passports, and visas; and background screening results and references.

• Career information
  such as job titles; work history; work dates and work locations; information about skills, qualifications, experience, publications, speaking engagements, and preferences; and professional memberships

• Education Information
  such as institutions attended, degrees, certifications, training courses, publications, and transcript information.

• Legally protected classification information
  such as race, sex/gender, religious/ philosophical beliefs, gender identity/expression, sexual orientation, marital status, military service, nationality, ethnicity, request for family care leave, political opinions, and criminal history.

• Other information
  such as any information you voluntarily choose to provide in connection with your job application.

• How We Use Personal Information

We collect, use, share, and store personal information from job applicants for our and our service providers' business and operational purposes in the recruitment process such as: processing your application, tracking your application through the recruitment process, contacting references with your authorization, conducting background checks you authorize, and making hiring decisions. We will also use job applicant information for internal analysis purposes to understand the applicants who apply and to improve our recruitment process. We may sometimes need to use applicant information for legal purposes, such as in connection with any challenges made to our hiring decisions.

• With Whom We Share Personal Information

We will disclose job applicant personal information to the following types of entities or in the following circumstances (where applicable):

• Internally
  : to other Legion personnel involved in the recruiting and hiring process.
• Vendors
  : such as technology service providers, travel management providers, human resources suppliers, background check companies, and employment agencies or recruiters, where applicable.
• Legal Compliance
  : when required to do so by law, regulation, or court order or in response to a request for assistance by the police or other law enforcement agency.
• Litigation Purposes: to seek legal advice from our external lawyers or in connection with litigation with a third party.

• Business Transaction Purposes
  : in connection with the sale, purchase, or merger.

• How to Contact Us About this Policy – If you have any questions about this Policy, please contact