Certificates in using software don't really matter much in getting hired, because these skills can be taught quickly during the first weeks of work and managers want you to use the software their way. Just having used the software for a year would be enough to check it off.
What you should do is to keep in touch with as many classmates as you can on LinkedIn. My first job was through a classmate that I met once in a group project, just enough to know that I was not a bully.
Make sure that you job application does not have any grammar mistakes. This applies no matter where you are from, but prejudice can make things worse if you apply to other countries.
Only showcase your best open source projects. Too many tiny projects can make it appear like the projects were made just for show without passion for development. Doing all projects on your own makes them ask if you can work with other developers.
Many large companies hire using middle management that does everything to climb the ladder and will be afraid of people who has the degree in management that they didn't get before getting promoted.
Don't waste time applying to lots of jobs with the same standard resume. A combination of filtering and writing targeted resumes using a reinforcement learning algorithm can land an interview on 50% of the job applications even if long time unemployed with a disability.
The filtering is about finding the companies with few applicants that list precisely your skills and hired from your age group recently. Look at the ratio of applications leading to an interview for each type of company and stop applying to those that would never give an interview.
My method for writing targeted resumes is to amass a large collection of descriptions targeted towards different types of companies based on industry, position, size, culture, male/female ratio. You have to dig deep to present who you really are with a few inspiring words that grab the attention of skimmers. Then give each piece one point up for each interview you got, unless you overreached and flunked their questions. One should not mistake getting interviews for setting too high expectations with getting closer to landing a job, but interview rate is still the best objective metric. Then you can piece together the best performing descriptions of yourself for each category and do a quick rewrite to remove some duplicate information, add anything relevant that's missing (check off all requested skills from the job post) and make it sound fluent while reading as a single piece. Writing poetry or novels as a hobby will help in writing fluent and evocative resumes.
If applying for a management role, it's all about the old writing technique called "show don't tell". Instead of listing lots of projects as a leader without any explanation, get into the shoes of the position you apply for and share your secrets to a happy performing team with advanced psychology terms and references to relevant scientific papers. Give examples from real life that shows your ability to lead with listening skills rather than pushing people off the edge. The message of who you are is more important than how high the position was. Your language should subtly project a calm and modest confidence, like someone who can tell everyone during crunch-time that it's going to be okay when the workers are stressed out and looking to the leader for reassurance. Most people who wants a leadership role come off as just wanting more pay for less work.
Hope this helps