Spelling mistake words:

davelopment (development), cantributing (contributing)

Wrong sentences:

None, but the last line is a fragment and not a full sentence, "I envision cantributing significantly to you company's goal of expanding into new markets and enhancing products offerings."

Suggestions:

1. Correct the spelling mistakes. "I see myself as a senior software engineer, leveraging my expertise in back-end development..."
2. Make sure to use full sentences. Instead of "I envision cantributing...", it would be better to say, "I envision myself contributing significantly to your company's goal of expanding into new markets and enhancing product offerings."
3. Use the correct pronoun for indicating possession. Instead of "you company's goal", it's "your company's goal."
4. Ensure coherence in your tenses. While you started with future tense ("I see myself..."), the statement "I'm passionate about staying..." switches to present tense. It would be better to maintain the same tense throughout. Consider saying "I will be passionate about staying..."